Environmental Chemistry Fall 2024 PDF

CHEMISTRY OF ENVIRONMENTAL POLLUTION A S S T. P R O F. M. F I R AT İ L K E R BOĞAZİÇİ UNIVERSITY C H E M I S T R Y D E PA R T M E N T FA L L 2 0 2 4  Anthropogenic Impact: Let’s start by looking at numbers... What is the current state of envir...

CHEMISTRY OF ENVIRONMENTAL POLLUTION A S S T. P R O F. M. F I R AT İ L K E R BOĞAZİÇİ UNIVERSITY C H E M I S T R Y D E PA R T M E N T FA L L 2 0 2 4  Anthropogenic Impact: Let’s start by looking at numbers... What is the current state of environmental chemical pollution? ❖ Today global production of anthropogenic substances (man-made chemicals) is more than 500 million tons/year (OECD and other references). 50 years ago it was 5 million ton/year. (As a comparison, Thames River (in UK, 350 km long) contains about 20 million tonnes of water) ❖ There are more than 100.000 synthetic chemicals used in everyday products (Solvents, detergents, dyes, hormones, antibiotics, surfactants, pesticides, mineral oil products, etc… ). ❖ Global annual production of petroleum based liquid fuel oil is about 3 billion tonnes. Some of this quantity is released to nature through spectacular accidents and leaks. The rest converted into combustion products. ❖ There are more than 300 man-made chemicals found in the blood stream of all people tested around the world. 2  What is the impact of these chemicals to Nature, to human body? 3  Some of the important titles to look at in order to answer the above question: What is the impact of chemical pollution?.. ❖ AIR POLLUTION and CLIMATE Ozone Depletion Photochemical Smog Acid Rain Greenhouse Gases Global Warming and Dimming ❖ Liquid and Solid Pollutants- LAND and WATER POLLUTION Polymers and Plastic Pollution Toxic Metals Organic Anthropogenic Chemicals ❖ ENDOCRINE DISRUPTING CHEMICALS 4  LIQUID and SOLID POLLUTANTS- LAND AND WATER POLLUTION- some of the important examples 5  Some key terms to understand the extend of pollution ❖Persistent pollutant: Resistant to environmental degradation through chemical, biological, or photolytic processes. ❖ Bioaccumulation: Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost. ❖Biomagnification: Persistent pollutant concentration increases progressively as it moves up a food chain. ❖Global Distillation: Persistent organic pollutants (POPs), are transported from warmer to colder regions of the Earth (Poles and mountain tops). 6  Natural Elemental Cycles / Anthropogenic Contributions The path atoms take from the living (biotic) to the non-living (abiotic) world and back again is called a ‘biogeochemical cycle’. Examples: Carbon cycle (below), Phorphorus cycle, Nitrogen cycle, Sulfur cycle… 7  Phorphorus cycle: Large scale anthropogenic contributions arise from phosphate fertilizers 8 Some drawbacks of fertilizers (!!!) 1) Promote growth of harmful insects 2) Keep plant roots short, weakening the plant 3) Causes nitrate accumulation in plants, later causing the formation of nitrosamines when eaten with meat 9 Global nitrogen fertilizer use has reached approximately one hundred million tonnes/year in 2010. According to latest ‘Planetary Boundaries’ studies, N and P elemental cycles were disrupted by human activity to a dangerous level, negatively affecting the future of life… 10 Planetary Boundaries: Safe operating space 11 12 The biogeochemical cycles of nitrogen and phosphorus have been radically changed by humans as a result of many industrial and agricultural processes. Fertilizer production and application is the main concern. Human activities now convert more atmospheric nitrogen into reactive forms than all of the Earth's terrestrial processes combined. Much of this new reactive nitrogen is emitted to the atmosphere in various forms rather than taken up by crops. When it is rained out, it pollutes waterways and coastal zones or accumulates in the terrestrial biosphere. Similarly, a relatively small proportion of phosphorus fertilizers applied to food production systems is taken up by plants; much of the phosphorus mobilized by humans also ends up in aquatic systems. A significant fraction of the applied nitrogen and phosphorus makes its way to the sea, and can push marine and aquatic systems across ecological thresholds of their own (algal blooms, loss of biodiversity…) 13  Polymers and Plastic Pollutants ❖ Plastic means mouldable (shapable), now most are man-made, generally non-degredable or very slowly degrading high molecular weight, chain like macromolecules. Generally, the breakdown of large polymers to carbon dioxide (mineralization) requires several different organisms, with one breaking down the polymer into its constituent monomers, one able to use the monomers and excreting simpler waste compounds as byproducts and one able to use the excreted wastes ❖ Plastics are persistent, they accumulate and reach places that they can have negative effects over time. ❖ While global annual plastic consumption was 5 million tonnes in 1950, today it reaches to more than 300 million tonnes. An estimated 56% of plastics are used in packaging. By 2015, the total cumulative mass of plastics produced was calculated to be around 5 billion tonnes, enough to coat the planet by a plastic wrap. 14  Plastics are persistent!  PET : most produced plastic polymer which is used in drink bottles, meal trays etc. (# 1)  HDPE : in milk bottles, wash-up liquid bottles etc. (# 2)  PVC : in food trays, water bottle,shampoo etc. (# 3)  LDPE : in carrier bags etc. (# 4)  PP : in meal trays, margarine containers etc. (# 5)  PS : in yoghurt pots, meat and fish trays, food boxes, egg cartons, packaging for electronics (# 6)  PC : in baby and water bottles, sports equipment, medical and dental devices, CD, DVDs etc. (# 7)  Others : PC, nylon etc. (# 7) 15  PET PS PE PP PVC PC 16  One solution for plastic pollution is recycling! Recycling processes include collecting and reprossessing of plastics by heat into different forms. In UK, 7% of total plastic waste was being recycled between 2000-2010. ❖ Benefits of recycling; Reduction of energy consumption during manufacturing by 2/3 (4% of world annual oil production is used as feedstock). 1/3 reduction in SO2 and NO2 release to atmosphere. 90% decrease in water use during manufacturing. Reduction of CO2 generation by 2.5 times (2 tonnes of oil are saved for every ton of PE produced). 17 ❖During plastic production, small molecular chemicals are used as feedstock or additives. Most of these additives have not undergone toxicology assessments. As plastic decompose over decades it slowly releases harmful additives and decomposition products to the environment. ❖ Where plastics go? 80% of plastics : sent into landfills, oceans, deserts... 8% : incinerated (potentially producing harmful chemicals) 7% : recyled 18 ❖ > 10% of the World’s plastic waste goes to the oceans and seas. In Pacific Ocean, 100 – 500 million tonnes of plastics exist. A total of 5 billion tonnes of plastic is estimated as a result of entire plastic production Pacific Garbage Patch : Plastics are broken down into plastic dust where marine wildlife mistakes for food. (6 kilos of plastics for every kilo of plankton) ❖ Not all plastics float, some sinks to the bottom of sea. More than 600.000 tonnes of plastics have been found to have accumulated in the bottom of North Sea. 19 MICROPLASTIC POLLUTION Microplastics are plastic pieces smaller than 5 mm in size. Plastic debris that starts off as macro- can become micro- through degradation and collisions that break it down into smaller pieces (micro- or nano-fragmentation). In 2014 total global amount of microplastic pollution was estimated to be in the range of 90000- 240000 tonnes. These micro-plastics can accumulate in the oceans and allow for the accumulation of Persistent Bio-accumulating Toxins such as DDT and PCB's which are hydrophobic in nature and can cause adverse health affects. Microplastics have been found to be accumulating in oceans, fresh waters, soil, air, and in tissues and bodies of several species, especially aqueous organisms, and human via fish… 20  PLASTIC ADDITIVES Plastics contain many additives (smaller molecules) such as plasticizers (plastic softeners), antioxidants, dyes, fillers. Many of such additives have not undergone toxicological assessments. They are not covalently attached to polymer (plastic) matrix. They can leach out and be absobed through skin. Examples: - Unreacted monomers (styrene, acrylics, BPA, etc.) - Phthalates as plasticizers (dozens of different phthalates, with oily/waxy appearances)  B I S P H E N O L - A ( B PA ) BPA is used in plastics for over 60 years (today 6-7 mill.tn./year): BPA Used as monomer in common types of epoxy resins (including those that are used in inner coatings of beverage cans)... And in most common type of Polycarbonate: Baby and water bottles, sports equipment, medical and dental devices, denta filling sealants, CDs and DVDs, household electronics, eyeglass lenses, and the lining of water pipes.Also used in the synthesis of polysulfones and polyether ketones, as an antioxidant in some plasticizers, and as a polymerization inhibitor in PVC !!!  B PA BPA is an endocrine disruptor at low very doses, found in blood stream of the majority of population (95% in USA in 1995), demonstrated to induce growth of prostate cancer cells in test animals. Prenatal exposure in humans is strongly suspected to cause life long effects such as obesity, brain development and memory problems, hyperactivity, thyroid disorders, alteration in breast development, increase in breast and prostate cancer risk, decrease in female fertility.  BPA is a xenoestrogen 1000- 2000 times less active in binding estrogen receptors DES is a more estrogenic derivative of BPA, used in treatment of pregnancy complications or cancer treatment between 1940- 1971, causing cancer, infertility, spontaneous abortion, irregular menstrual periods, obesity, developmental problems, male impotence, transsexual changes, depression, etc. 24 More examples of structural similarities between Estradiol and some commercial compounds in everyday use: Common Tetrabromo BPA examples of brominated flame retardants, used in plastics, papers etc. Estradiol 25 ENDOCRINE DISRUPTING CHEMICALS (EDCs) 26 ❖ Endocrine disruptors are chemicals that, at certain doses, can interfere with the endocrine (or hormone system) in mammals. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders such as learning disabilities, severe attention deficit disorder, cognitive and brain development problems; deformations of the body (including limbs); obesity; immune disorders; breast cancer, prostate cancer, thyroid and other cancers; sexual development problems such as feminizing of males or masculinizing effects on females, etc. 27  ENDOCRINE DISRUPTING CHEMICALS (EDCs) Some medical indications that lead to understanding of EDCs ❖ Nearly 8 % of births in 2007 were the result of artifical insemination, that is, in vitro fertilisation, insemination and donor insemination. ❖ Sperm quality decrease is widespread. ❖ High rate of testicular cancer which have actually quadrupled in 60 years. It is shown to be caused by events in the feotal stage. ❖ Analyses in umbilical cord and mother milk show presence of antropogenic chemicals that can be transferred from mother to baby. Fat soluable POPs go into the baby’s growing body and brain. 28 An important remark from a well known expert of the field:  Ake Bergman, Professor in Environmental Chemistry, Board Member of International Panel on Chemical Pollution, in his 2010 press release on the web about Brominated Flame Retardants (known EDCs): «...society did not comprehend the serious threat that the persistent and reactive BFRs pose to life. Independent of the corpus that all chemicals are toxic if the dose is high enough, as first presented by Paracelsus almost 500 years ago, only accidents with severe human symptoms or casualties make societies able to act. What did we then learn from the PCBs, DDT, HCB, PBBs, PCDDs, PCDFs, the «drins», toxaphen, mirex, chlordane, heptachlor...?» 29  Toxic Metal Pollution (Hg, Pb, Cd, Cr, Zn, Cu, Ni, Co, Se…) Toxic metal pollutants (most are considered as heavy metals) are persistent, generally bioaccumulate and biomagnify, some have strong EDC properties. As, Pb, Cd and Hg are included in the list of ’Ten chemicals that cause major public health concern’ of WHO (World Health Organization). 30 LEAD Pb : Globally 600,000 new cases of children with intellectual disabilites is attributed to Pb pollution. Pb is bioaccumulating. Pb exposure is suspected to cause 0.6% of all global burden of diseases. Inhibits heme (hemoglobin) biosynthesis by inhibiting several key enzymes. It can replace essential cations such as Ca2+, Mg2+, Fe2+ in the body. Binds to sulfhydryl (-SH) groups of proteins. Causes excessive formation of peroxides in the body, and depletes antioxidant reserves. Causes acute toxicity, or chronic toxicity (lead palsy, lead colic, lead encephalopathy, neurotoxic effects, problems in hematologic, gastrointestinal, cardiovascular, and renal systems). It can affect the developing brain. Exposure to lead in the womb can lead to a lower IQ, as well as learning and behavior problems that can last a lifetime. Recent animal studies (2018) reveal a link between early exposure to lead and Alzheimer’s disease later in life, through epigenetic mechanisms. Released through fuel burning (coal etc.), used as fuel additive in the form of tetraethyl lead (road dust example).. It also commonly originates from metal smelting, chemical industrial uses, leaded paints, plastic additives and electronics/batteries (lead acid battery etc.). Tetraethyl lead, PbCrO4 (PbII, yellow), Pb3O4 used to be a (PbII,IV red), PbCO3 (PbII, common fuel white), were commonly used additive as pigments in paints 31 Pb (Lead): Pre-industrial human measurements estimated blood lead levels to be around 0.016 µg/dL. USA Pb blood levels were about 16 µg/dL in 1976, 3 µg/dL in 1991 after Pb bans, most importantly the ban in leaded fuel. Pb reductions were associated with 50-60% drop in crime rates between 1992-2002 in USA!!! Lead was suggested to cause agressive and violent behavior in the exposed population. Lead is well known to have very strong neurological adverse effects. Before 1990’s lead poisoning in children had become a widespread problem all around the world. For example car exhausts were releasing Pb particles as the most common source of widespread Pb pollution, children were eating pieces of old paints falling out of walls, and suffer from lead poisoning. Eventually lead was banned from fuels, paints and plastics. No level of lead in the blood of children is currently thought to be safe, but for example the US- CDC identified 10 μg/dL as a level of concern before 2012, and since 2012 has identified 5 μg/dL as an amount of lead that should prompt further medical investigation. Approximately 1 in 40 American children have at least this much lead in their blood. Lead is a still a pollutant that cause health concerns all around the world. Old municipal or local water pipes that were commonly made of lead can release this toxic metal into water. In 2014 old leaded water pipes caused a health crisis in Flint, Michigan/USA. The problem was that the city’s supply was changed to a river that had very corrosive water, and this water made lead leach into the water. 85% of children diagnosed with high blood lead levels (approximately doubled) in 2016. 32 Legally-binding controls on lead paint (2021, WHO) 33 Mercury (Hg) : Released naturally from volcanoes, and anthropogenically by coal burning, gold production, waste incineration, metal mining (historical gold mining), cement production, chlor-alkali industry... Found as neutral metallic mercury, or salts of Hg(I), or Hg(II). Global Hg emissions to atmosphere is around 2500 tons/year, 1/3 of it is estimated to be from natural sources. Asian countries contribute about 55 % (China 28%) through their various industries. Mercury, and especially some of its compounds (e.g. Methyl Mercury (solid, MeHg+X-), dimethyl mercury (Me2Hg, volatile)) are highly toxic, persistent endocrine disruptors. Methyl mercuries are formed by a process called biomethylation, caused by certain types of bacteria. MeHg+ binds to lipids, also to protein and peptides containing thiol groups (glutathione and cysteine), and to DNA (interferes with transmission of genetic info negatively affecting protein synthesis). 34 An example of mercury biomethylation mechanism. The methyl group originating from the serine amino acid is transferred to the THF and after to cobalamin. The methylcobalamin molecule acts as a methyl donor, methylating the Hg2+ Ref: P.A. Nogara, et al. BBA - General Subjects 1863 (2019) 129284 35  cysteine Neurospora crassa, fungus Another example of mercury biomethylation mechanism. Proposed MeHg formation from Neurospora crassa. In this case, MeHg is formed due to an error in the methionine synthesis from free homocysteine. Ref: P.A. Nogara, et al. BBA - General Subjects 1863 (2019) 129284 36 The latter complex being structurally similar to natural essential amino acid methionine, it moves easily through bodily barriers (e.g. Blood brain barrier). The blood–brain barrier (BBB) is a highly selective border that separates the circulating blood from the brain and central nervous system. BBB allows the passage of some molecules by diffusion, as well as the selective transport of molecules such as glucose, water and amino acids that are crucial to neural function. 37  The biological half-life of MeHg is 39 to 70 days depending on body burden. But smaller quantities may get stuck in various parts of the body... Potential sources of organic mercury: Exposure to fossil fuel emissions, The incineration of medical waste, Dental amalgam, Various commercial products including skin creams, germicidal soaps, various medications, teething powders, analgesics, diaper treatments, vaccinations, thermometers, sphygmomanometer, barometers, incandescent lights, and batteries. 38 Toxicology: Mercury poisoning can result in death, mental retardation, dysarthria, blindness, neurological deficits, loss of hearing, developmental defects, and abnormal muscle tone. Systemic exposure is hold responsible of about 250 illnesses including problems in: Cardiovascular, hematological, digestive, renal, immune, nervous, endocrine (e.g. Thyroid) and reproductive systems. Prenatal exposure remarkably increase risks of health problems later in life. Minamata disease: Accidental Hg release in 1956 in Minamata Bay - Japan, estimated to be around 80 tonnes, fishes were contaminated, animal and human deaths continued for 36 years. Only in 2001 victims got partial compensations. An accumulated dose of 50 mg makes a person unable to work, 200 mg causes death. 39 Environmental Hg levels in an intermediate contaminated area (A) and an extremely contaminated place, Minamata Bay during the outbreak of Minamata disease in Japan (B). Hg is released in the environment by natural (volcanism or erosion) and by anthropogenic sources (waste of factories, biomass burning, and gold mining, among others). In the aquatic ecosystem, Hg species can be methylated, oxidized or reduced by the microorganisms. The biomagnification of MeHg in the food chain can be 1–6 orders of magnitude over the levels of Hg found in the water and sediments. In the atmosphere, Hg species can be demethylated, oxidized or reduced by physical- chemical processes. In the Minamata outbreak, large quantities of Hg were released into the bay. The sludge in the Bay, in 1978 had 250 to 7000 ppm of Hg. The outbreak in Minamata Bay was a case of extreme exposure, with marine fauna Hg levels ranging from 5 ppm (oysters) to 40 ppm (crabs and fish). The adult population presented Hg hair levels varying from 2.46 ppm (minimum) to 705 ppm (maximum). The 30- fold variation between minimum to maximum hair Hg levels in the Minamata Bay population may be related to differences in the consumption of seafood. As a consequence of high levels of MeHg+ in the diet of pregnant and/or lactating women, infants from Minamata Bay who were exposed via utero and/or breastmilk exhibited severe neurological problems ranging from dysarthria to mental retardation and cerebral palsy. Ref: P.A. Nogara, et al. BBA - General Subjects 1863 (2019) 129284 40 GSH: Glutathione Theoretical distribution and binding of MeHg+ to –SH and –SeH molecules at different levels of exposure. Ref: P.A. Nogara, et al. BBA - General Subjects 1863 (2019) 129284 41 Arsenic (As) : Major pollutants are salts of As+3 , As+5. They are absorbed through GI track and inhalation. Soluble inorganic As is acutely toxic (arsenic poisoning can kill), then depending on the exposure level (the dose) As can cause skin lesions, neuropathy, gastrointestinal problems, cardiovascular diseases, cancer. Found in Earth’s crust and underground waters in certain regions. In certain regions, As is naturally found in groundwater, and in crops which are irrigated with As contaminated water. E.g. in Bangladesh ~9000 deaths in 2001. Accumulates in lung, heart, kidney, liver, muscle, neural tissue, concentrates in skin, nails, hair. Half-life is 7 to 10 hours. Inhibits anaeorobic and oxidative phosphorylation, inhibits sulfhydryl containing enzymes… Released mostly through metal mining, especially gold mining as As-Au coexist. Also common as semiconductor AsGa, and as herbicide and pesticide… 42 Cadmium : Toxic to kidney, possible cause of skeletal and respirotary diseases, lung cancer, etc. It is the cause of Itai-Itai disease (very painful and possibly lethal bone disease). It is absorbed mostly through inhalation. Binds to albumin (A 65-70 kDa blood transport protein), primarily on tryptophan then to tyrosine residues, leading to protein aggregation and partial unfolding (denaturation). Cadmium is known to increase oxidative stress by being a catalyst in the formation of reactive oxygen species, increasing lipid peroxidation, and depleting glutathione (a natural antioxidant preventing damage to important cellular components caused by reactive oxygen species such as free radicals, peroxides, lipid peroxides, and heavy metals). It can also stimulate the production of inflammatory cytokines and downregulates the Tryptophan protective function of nitric oxide formation (NO dilates blood vessels, raising blood supply and lowering blood pressure). Cadmium causes mutations, DNA strand breaks, chromosomal Tyrosine damage, cell transformation and impaired DNA repair in cultured mammalian cells (NTP 2004). The U.S. National Toxicology Program (NTP) Glutathione has characterized cadmium as known to be a human carcinogen. 43 Cd displays Zn like properties and coexist with Zn ores… Accumulates in liver, kidney, muscle and bone tissues… The total cadmium body burden at birth is non-detectable (U.S. CDC 2005). It gradually increases with age to about 9.5 mg to 50 mg (U.S. ATSDR 1999). It has an average half- life of 10-15 years in human body (6-38 in kidney, 4-19 in liver…), causing muscle and bone loss, chronic back pain, chronic depression, agressive behavior, tendency to violent behavior, IQ loss, hypoglycemia, hypertension, etc. It is commonly emitted from various mining operations. Used in phosphate based fertilizers, NiCd batteries, electroplating, plastics… 44 Aluminum (Al): The third most abundant element in Earth’s crust (after oxygen and silicon). Aluminum and its alloys are important materials for transportation, construction, electronic and packaging industries. Also commonly used in paints, fuel additives, explosives. Aluminum oxides are used as food additives, aluminum hydroxides in pharmaceuticals. The aluminium oxides and sulfates are the most useful compounds of aluminum. Aluminum is the most widely used non-ferrous metal. The global production of aluminum in 2016 was 58.8 million tons (55% of production is in China). Most aluminum consumed will leave the body in feces; the small part of it that enters the body, will be excreted via urine. Aluminum that stays in the body is accumulated in, above all, bones; and apart from that, in brain, liver, and kidney. At elevated body exposure Aluminium can cause encephalopathy (chronic degenerative brain symptoms such as intellectual disability, irritability, agitation, delirium, confusion, somnolence, stupor, coma and psychosis). Because some of these symptoms overlap with Alzheimer’s disease caused dementia symptoms, and because dementia patients may have high Al accumulation in their body/brain, Al is suspected to cause Alzheimer’s disease, or at least resulting in similar symptoms. 45 Exposure to metals can be in one accidental case, leading to fast appearance of symptoms. Chronic exposure to small doses may lead to appearance of symptoms throughout time, as they accumulate towards higher levels in the body. Metals can be found in the body within certain range of concentration, for well functioning at the cellular level. If not within the necessary range they may cause serious health problems. Since metals tend to bioaccumulate to some extent, depending on the type and form of metal, chronic exposure commonly leads to increased accumulation in the body, causing metal poisoning symptoms to appear at some point in life. Common metal poisoning symptoms:  Headache  Weakness and tiredness  Achy joints and muscles  Gastrointestinal problems  Depression (very common symptoms in general population) 46  Organic Anthropogenic Chemicals ❖ BTEX Compounds benzene toluene ethyl benzene xylene (tiner=thinner) Carcinogenicity ↓-----→  petroleum products (top 20 in production volume in US)  used in chemical manufacturing (solvent, additive etc.) 47  Pesticides: Insecticides/Herbicides/Fungicides Pesticides are persistent, bioaccumulative. Types: Organochlorine insecticides (Oldest types, 1930s-1980s- now banned, can be found in the black market) Organophosphate pesticides (Majority of them are banned, but...) Carbamate pesticides Pyrethroid pesticides Sulfonylurea herbicides Neonicotinoids (starting 1980s, by Shell and Bayer) Glyphosate herbicide (Currently by far the most widely used herbicide) ❖ While there was 30 substances in use 40 years ago, the spectrum is around 400 (about 350 in use in Turkey) substances today. Currently multiple pesticides (up to 15-20) are used for most agricultural products. 48  Pesticides: Insecticides/Herbicides/Fungicides 1 LBS = 454 gr Total global use is near 2.5 thousands tonnes in 2012 Source: US EPA 49 Source: US EPA 50  Pesticides ❖ DDT (organochlorine): dichlorodiphenyltrichloroethane ❖ It is banned in 1972 in USA followed by Europe. Included in Stockholm Convention (2004) that restricts the use of some harmful POPs. ❖ Rachel Carson’s book: “persistent, bioaccumulative «Silent Spring» lead to public and biomagnifies” reaction and banning (!) ❖ From 1950-1970, it was extensively used worldwide in agriculture, approximately 400.000 tonnes/year 51  Pesticides ❖ DDT goes into adrenalin gland and produces stress hormone cortisol. First accumulates and then breaks down there and produce a very aggressive substance, which attacks the adrenal cells and destroy them. The end result is that your ability to produce cortisol will diminish.  Environmental degradation product is DDE which is very stable. Weak androgen receptor antagonist and it can produce male genital tract abnormalities.  Animal studies show that organochlorine pesticides, such as DDE, are neurotoxic, cause oxidative stress, and damage the brain's dopaminergic system. 52 Chlorpyrifos (organophosphate) Banned in US in Aug 2018. Just banned in Turkey (??), several types of fruits (oranges, lemons) and vegetables are exposed… It was introduced in 1965 by Dow Chemical Comp. It acts on the nervous system of insects by inhibiting acetylcholinesterase (neurotransmitter) Parathion, banned in many countries (Germany 2002) Malathion. Can cause ADHD in children, and types of cancer… 53  Carbaryl insecticide (carbamates) Cyhalothrin, a type of pyrethroid Nerve agent… Derivatives also used as (household chemotherapy (ethyl carbamate, toxic), and insecticides) in cosmetics as preservatives Neonicotinoid - Imidacloprid Pyrethroids are toxic to beneficial insects such as bees, dragonflies, mayflies, ga Glyphosate herbicide dflies, and some other invertebrates, including those that constitute the base of aquatic and terrestrial food webs. They are toxic to aquatic From 1999 through at least Latest most widely used herbicide, organisms including 2018, imidacloprid was the most may cause types cancers, and fish, possibly at extremely small widely used insecticide in the Colony Collapse Disorder (Bees world.Banned in Europe since 2018! levels, such as 4 parts per trillion. Colonies) !!! Poses high risk for bees, endangered or (Wikip.) thretened species and critical habitats. 54 https://www.tarimorman.gov.tr/Konu/934/Yasaklanan-Bitki-Koruma-Urunleri-Aktif- Madde-Listesi (20/11/2019) https://www.tarimorman.gov.tr/Konu/934/Yasaklanan-Bitki-Koruma-Urunleri-Aktif- Madde-Listesi (20/11/2019)  PCBs – Polychlorinated biphenyls ❖ PCBs (130 congeners) polychlorinated biphenyls (prepared by electrophilic chlorination) ❖ widely use in; lubricants hydrolic liquids dielectric fluids transformers capacitors coalents plasiticizers Oderless, tasteless, clear pole yellow, paints viscous liquid stabilizers in PVC flame retardants ‘persistent, bicoaccumulative (half-life adhesives near 10-15 years, biomagnifying’ cosmetics 57  PCBs ❖ PCBs has been banned since 1979 in most part of the world because of its high toxicity. Stockockholm Convention brought global restriction in 2001. ❖ Total global production of PCBs was 1.5 million tons Monsanto Company in USA was the single largest producer with 600.000 tons of production between 1930-1977. Europe produced 450.000 tons ❖ PCBs are well known EDC (human carcinogen, developmental problems, thyroid problems, cognitive and immune disorders etc.), they have wide range of toxic effects, also shown to alter transcription of genes. Binds to AhR transcription factor (aryl hydrocarbon receptor). 58  Brominated Flame Retardants- BFRs ❖ Bioaccumulating and persistent. All commercial plastics contain them. ❖ PBBs (Polybrominated biphenyls). Banned for several decades but still ubiquitous in the environment worldwide. ❖ PBDE (polybrominated diphenyl ethers). Replaced PBBs, but then banned during 2000s after being widely used in textiles and electronics as flame retardant. Strong EDCs, cause neurobehavioral problems, human carcinogen. Globally 70.000 tonnes per year 59  Dioxins: PCDDs, PCDFs --- Products of incomplete combustion. They are formed when carbon based organic material is burned in less-than-optimal conditions such as open fires, building fires, domestic fireplaces, and poorly-operated and/or designed solid waste incinerators. --- Most congeners are toxic and have strong EDC properties (cause cancer, reproductive problems, sexual development problems, immune disorders, thyroid, diabetes) 60 How can you be exposed to dioxins and furans? You can be exposed to dioxins and furans by eating contaminated food. They typically stay and build up in the fatty tissues of animals. This means that eating beef, pork, poultry, fish as well as dairy products can be a source of dioxin/furan exposure. There are several sources of exposure to dioxins and furans. If you work in or near a municipal solid waste incinerator, copper smelter, cement kiln or coal fired power plant you can be exposed to dioxins and furans. Individuals who burn their household waste or burn wood can be exposed as well. Even forest fires can contribute to the creation of small amounts of dioxins and furans. Dioxins and furans have been found in the air, soil, and food. Dioxins and furans are mainly distributed through the air. However, only a small percentage of exposure is from air. Eating contaminated food is the primary source of exposure. What are the health effects of exposure to dioxins and furans? Dioxins and furans can cause a number of health effects. The most well known member of the dioxins/furans family is 2,3,7,8 TCDD. The U.S. Environmental Protection Agency (EPA) has said that it is likely to be a cancer causing substance to humans. In addition, people exposed to dioxins and furans have experienced changes in hormone levels. High doses of dioxin have caused a skin diseased called chloracne. Animal studies show that animals exposed to dioxins and furans experienced changes in their hormone systems, changes in the development of the fetus, decreased ability to reproduce and suppressed immune system. What levels of exposure have resulted in harmful health effects? The U.S. EPA has set a limit of 0.00003 micrograms of 2,3,7,8-TCDD per liter of drinking water (ug/L). The Food and Drug Administration recommends not eating fish and shell fish with more than 50 parts per trillion (50 ppt) of 2,3,7,8-TCDD.  Phthalates ❖ They are ubiquitous, widely used as additive in; cosmetics children toys cleaning agents construction ❖ Phthalates constitute of 40 % of mass of toys to soften it. After touching a toy, it makes fingers oily. This feeling disappears quickly because the body absorbs it. They possess strong EDC properties. Cause multiple type of cancers. 63  Large variety of Medicinal chemicals: Antibiotics, Birth Control Pills, Hormones...  One important example out of hundreds: Female hormone Oestrogene derivatives and oestrogenic compounds: 17β-Estradiol At ng/L concentrations they have been shown to cause multiple deformations in certain types of fish and frogs, including the «feminization» of male fishes and frogs 64  PARABENS Found in about half of all personal care products, parabens and their degradation products are heavily released from waste water effluents. Chlorinated Parabens (through reaction with HClO /NaClO) are not easily removed by WWTPs. Their endocrine disrupting potential increases as their ester chain increases. Harmful to aquatic life. The list of POPs and other ubiquitous anthropogenic chemicals goes on...  Polyfluorinated organic substances (PFOS): Extrememly persistent, absorbed in the body rendering cells to be more permeable, some are endocrine (Thyroid) disruptors...  Some ethers, e.g. Methyl-tert-butyl ether (MTBE), affects nervous system, cause cancer depending on dose...  Alkyl Phenols, e.g. Nonyl-phenol, mimics oestrogen hormone, endocrine disruptor...  Bisphenol-A (BPA), used in plastic production, high EDC activity at very low doses... .... .... 66 Some of the most common PFOs, ubiquitous in the entire environment 67 An Important target of Chemical Pollutants in Body: THYROID GLAND AND THYROID HORMONES Thyroid glands and the FINE BALANCE and TIMING of the production of thyroid hormones are responsible of development of body and brain. Hormone concentrations are especially crucial in brain development of babies at prenatal stage and first years after birth. Triiodothyronine Several POPs (PCBs, Dioxins, etc.) with similar chemical structures impair the Thyroid Function by: -Impairing Iodine uptake by the gland -Blocking the hormone making enzyme -Displacing the natural hormone in blood proteins impairig Thyroxine distribution and entry. 68 Some global statistics about iodine deficiency (WHO 2004) 69  Agonist/Antagonist in Biochemistry Agonist: An endogenous (e.g. natural hormones, neurotransmitters) or exogenous (e.g. drugs, pollutants) chemical that binds to a specific receptor and activates the receptor to produce a biological response. Antagonist: A chemical that blocks a specific biological response or the activity of an agonist, by binding to and blocking its target receptor. Also called ‘blocker’. For example: -Triclosan (a common antibacterial agent) is known to disrupt thyroid systems in laboratory rats and frogs. One possible pathway is through ‘agonism or antagonism’ to specific nuclear receptors that are responsible of regulating catabolic and transport activity. -Triclosan, may be an antagonist or weak agonist of the estrogen receptor and/or a weak antagonist of the androgen receptor. All deiodinase enzymes are selenoproteins (or selenoenzymes); that is, they all contain selenium (Se). 71 Mercury, its effect on Thyroid system: Organic mercury (such as in methyl or ethyl mercury) can be converted to inorganic mercury by microorganisms in the intestine. Inorganic mercury can persist in the brain for long periods. ***Inorganic mercury interacts with selenium, forming mercury selenite, HgSe, which is thought to be the form that is retained in the central nervous system. Cadmium has similar interactions with Selenium… 72 Structural comparison of some EDCs to thyroid hormones: Note all the compounds share strong structural homology with thyroid hormone (in this case T4 is depicted). It is also pertinent to recall that TBBPA is broken down to BPA in the environment, increasing BPA load. Reference: ‘Losing Our Mind’ book by B. Demeneix 73  TRICLOSAN Antibacterial agent developed in 1960s by Ciba-Geigy (now produced by BASF), commonly found in many products such as soaps, washing gels, shampoos, personal care products, toothpastes, pesticides, etc. USA-FDA (Food and drug administration) banned its use in consumer antiseptic washes, by september 2017. Ubiquitous in the environment, and found as a contaminant in human body, it is a weak endocrine disruptor an allergen. vs. Triclosan Triiodothyronine (natural hormone) Triclocarban, another antibacterial agent, with similar properties as triclosan  Triclosan (anthropogenic) Triiodothyronine (natural hormone) Both molecules share similar skeleton, major difference being presence of chlorine or iodine atoms surrounding the aromatic groups. Both chlorine and iodine are capable of forming ‘Halogen Bonds’. A parallel relationship can easily be drawn between halogen bonding and hydrogen bonding. In halogen bonding, a halogen atom is the electron acceptor. Iodine forms the strongest halogen bonds. Halogen bonds are strong, directional, and lead to specific binding angles. In the case of protein-ligand interactions, the most common charge-transfer bonds with polarizable halogens involve backbone carbonyls and/or hydroxyl and carboxylate groups of amino acid residues. Thyroid health problems result in a large range of symptoms such as obesity, depression, infertility, IQ loss…. 75  What happens when foreign chemicals in the body act together? Cocktail Effect!! Examples of ublished experiments reveal results such as: Four chemicals are tested individually for toxicity at concentrations that is below their LD50 : No harmful effect Same four chemicals at the same doses, when tested in combination: Very harmful health effects Cocktail effect is a phenomena that scientist are just beginning to study in the last years and we have very little knowledge about it.... 76 EPIGENETICS 77  EPIGENETICS: Environmental factors affect the gene functioning through activations or deactivations of genes, without a change in gene sequence. However these changes can be transmitted to next generation (heritable), if similar environmental factors continue to be present. DNA methylation and histone modification, each alters how genes are expressed without altering the underlying DNA sequence 78  Ülkemizde Atıksu Arıtma Tesisleri Çıkışında ÇKS Değerlerini Aşan Mikrokirleticilerin Listesi (TR 2017) 1 1,1-Dikloroetan 21 Asetamiprid 41 Dibutilkalay oksit 2 1-metilnaftalin 22 Azinfos-metil 42 Dieldrin 3 BBP 23 Azoksistrobin 43 Dietil Fitalat 4 1,1-Dikloroetan 24 B 44 Difenil eter; difenil oksit 5 1,2,4-trimetilbenzen 25 BBP 45 Difenilamin 6 1,3,5-trimetilbenzen; Mesitilen 26 Be 46 Diflubenzuron 7 1,3-diklorobenzen 27 Bentazon 47 Diflufenikan 8 1,4-diklorobenzen 28 Benzil benzoat 48 Diizobütil adipat 9 17-beta-estradiyol 29 Benzo(a)floren 49 Diklofenak 10 1-kloro-2,4-dinitrobenzen 30 Benzo(e)piren 50 Dimetenamid 11 1-metilnaftalin 31 Bifenil 51 Dimetoat 12 2,4-d; (2,4-diklorofenoksi)asetikasit 32 Bis(2-etilhekzil) terefitalat 52 Dimetomorf 13 2,6-di-ter-butilfenol;2,6-di-tersiyerbutilfenol 33 Bisfenol-A 53 DnOP 14 2,6-ksilenol 34 Boskalid 54 Epoksikonazol 15 2-amino-4-klorofenol 35 Bromoksinil 55 Etalfluralin 16 2-kloronaftalin 36 Buprofezin 56 Etoprofos 17 4-Kloro-3-metilfenol; Paraklorometakresol 37 DBP 57 Fenantren 18 4-kloroanilin 38 DDT Toplam 58 Fenarimol 19 Aldrin 39 Dekametilsiklopentasiloksan; Siloksan-D5 59 Feneksamid 20 Asenaften 40 Diazinon 60 Floren 61 Fludioksonil 81 Klorfenapir 101 p,p′-DDD 62 Fluopiram 82 Krisen 102 p,p'-DDE 63 Fostiazat 83 Ksilen (m) 103 p,p'-DDT 64 Hekzakonazol 84 Ksilen (o) 104 PCB 138 65 Hekzitiazoks 85 Ksilen misk 105 PCB 28 66 Imazalil 86 Lenasil 106 PCB 31 67 Imazapir 87 Linuron 107 PCB 52 68 Imidakloprid 88 MBT 108 Penkonazol 69 Isodrin 89 Metalaksil 109 Perilen 70 Izopropilbenzen 90 Metalaksil 110 Permetrin 71 Kadusafos 91 Metam potasyum 111 Piperonil butoksit 72 Karbaril 92 Metoksifenozid 112 Piren 73 Karbendazim 93 Metolaklor 113 Pirimetanil 74 Karbofuran 94 Metrafenon 114Prokloraz; N-propil-N-[2-(2,4,6-triklorofenoksi)etil]-1H-imidazol-1- karboksamid 75 Karbontetraklorür 95 Miklobutanil 115 Propamokarb HCL 76 Klofentezin 96 Molinat 116 Propetamfos 77 Klofibrik asit 97 n-bütilkalay triklorür 117 Propilbenzen 78 Klopiralid 98 Nikosulfuron 118 Siflutrin; beta siflutrin 79 Klorantraniliprol 99 Ometoat 119 Siprodinil 80 Klordan 100 p-(1,1-dimetilpropil)fenol 120 Siromazin 121 Stiren; Vinilbenzen Ülkemizde İçme Suyu Arıtma Tesisleri Çıkışında Yüksek 122 Sülfametoksazol KonsantrasyondaTespit Edilen Mikrokirleticilerin Listesi 123 Tebukonazol (TR 2017) 124 Teflutrin 125 Tiabendazol 1 Heptaklor epoksit 126 Tiakloprid 2 Diklorometan 127 Tiametokzam 3 Benzen 128 Tidiazuron 4 Tribenuron-metil 129 Tiofanat-metil 5 Asetaklor 130 Tolfenpirad 6 Fentiyon 7 Triklosan 131 TRI 8 Sipermetrin 132 Triadimenol; α-ter-bütil-β-(4-klorofenoksi)-1H-1,2,4-triazol-1- 9 Trikloro-metan etanol 10 Vanadyum 133 Tributil fosfat 11 Perklorat 134 Tridecane 135 Trifenilkalay; Fentin 136 Vanadyum  PESTICIDE POLLUTION IN SOIL AND WHEAT: RISK ASSESSMENT OF CONTAMINATED FOOD CONSUMPTION By:Beduk, F (Beduk, Fatma)[ 1 ] ; Aydin, ME (Aydin, Mehmet Emin)[ 1 ] ; Aydin, S (Aydin, Senar)[ 1 ] ; Tekinay, A (Tekinay, Arzu)[ 1 ] ; Bahadir, M (Bahadir, Mufit)[ 2 ] FRESENIUS ENVIRONMENTAL BULLETIN Volume: 26 Issue: 3 Pages: 2330-2339 Published: 2017 View Journal Impact Abstract In this study, organochlorine pesticides (OCPs) and organophosphorus pesticides (OPPs) contamination of wheat cultivated in Konya region and soils of this region were determined. Health risk caused by the consumption of pesticide contaminated wheat was assessed. Totally, 30 soil samples and 21 wheat samples taken from the field and trade center were analyzed for OCPs (alpha-HCH, beta-HCH, gamma-HCH, delta-HCH, aldrin, dieldrin, heptachlor, heptachlor epoxide, endosulfan I, endosulfan II, endosulfan sulfate, p,p'-DDE, p,p'-DDD, p,p'-DDT, endrin, endrin aldehyde, endrin ketone, methoxychlor) and OPPs (malathion, parathion, methyl-parathion, chlorpyrifos, diazinon). Determinations of OCPs and OPPs were carried out with a GC/MSD (GC, Agilent 6890 N, MSD, Agilent 5973). Maximum concentrations of OCPs in soil samples were found for Sigma HCHs (alpha-HCH, beta-HCH, gamma-HCH, delta-HCH) and Sigma endosulfan (endosulfan I, endosulfan II, endosulfan sulfate) in the range of 8.74 - 71.8 ng g(-1) and 1.99 - 112 ng g(-1), respectively. Malathion and chlorpyrifos were the predominant OPPs in soil and wheat samples. Maximum concentrations of malathion and chlorpyrifos in soil samples were 222 ng g(-1) and 556 ng g(-1), respectively. Maximum total OCPs and total OPPs in the grain were 2.32 mu g g(-1) and 15.4 mu g g(-1), respectively. Sigma DDT was found in the range of 20 60 ng g(-1) in grain samples. Trade center samples exceeded maximum residue limits (MRL) of Turkish Food Codex (TFC) given for beta-HCH, gamma-HCH, Sigma HCH, dieldrin and chlorpyrifos, and field samples exceeded MRL given for a- HCH, beta-HCH, Sigma HCH, Sigma endosulfan, Sigma heptachlor, and all OPP compounds. There is an acute and chronic consumer health risk due to the consumption of pesticide contaminated wheat, on the basis of aHI and HQ calculation. Besides, prohibited pesticides are obviously still being used in the area. [ 1 ] Necmettin Erbakan Univ, Dept Environm Engn, Konya, Turkey Show more [ 2 ] Tech Univ Carolo Wilhelmina Braunschweig, Inst Environm & Sustainable Chem, Hagenring 30, D-38106 Braunschweig, Germany Air Pollution 83  1.Ozone Depletion A natural belt of ozone (O3, a reactive molecule ) at 15-30 km (stratosphere) above the surface, and it shields harmful UV-B radiation emmitted by sun. Ozone layer was known since 1920s-1930s. Gordon Dobson developed the ‘ozone spectrophotometer’, measuring 305 nm UV absorption by ozone (at 325 nm not absorbing). Ozone layer is 400 D.U. (Dobson Unit, 2.7x1016 molecules/cm2) which makes 4 mm thick when brought to Earth’s surface. ❖ Ozone Depletion : slow, steady decline of about 4% per decade that has been observed since 1970s. ❖ Ozone Hole : a much larger depletion (up to 65%), seasonal depletion occuring in polar regions. First discovery by Joe Farman (British Arctic Survey) in 1984. 84  Stratospheric Ozone Depletion ❖ The largest hole in Antarctic (South Pole) was observed in 2006 (fall). This hole was about 10.6 million square miles (nearly the size of N. America). ❖ The largest hole in Arctic (North Pole) was observed in 2011, at the same size of the hole in South Pole that year. ❖ Holes in polar regions are expected to completely recover by 2060-2080, if ODSs were no more released. 85  Major Source of the Ozone Depletion Ozone Depleting Substances (ODS): Chlorofluorocarbon (CFCs), HCFCs, freons, halons. They are produced in large quantities to be used in air conditioning, cooling, aerosol sprays, solvents etc. in the past 50 years. (e.g. CHCl3, CCl4) CFCl3 sun radiation Cl + CFCl2 Cl + O3 ClO + O2 ClO + O3 Cl + 2O2 ❖ Cl radical reacts catalytically, single Cl radical can destroy 100.000 ozone molecules. ❖ Although Br radicals are more active, there is much less Br radical in atmosphere at present. ❖ 90 % of ODSs were emitted by industrial countries in the northern hemisphere. 86  Harmful effects of Ozone Depletion Thinner ozone leads to more UV-B radiation reaching Earth and it is suspected to result in:  Increase in skin cancer occurrence.  Increase in cataracts.  Damage to plants.  Large scale loss of phytoplanktons (especially in polar regions) 87  2. Photochemical Smog SMOG = Smoke + Fog ❖ First appearance was in England, 1883. ❖ CONTENT of Smog Aldehydes (RCHO) Nitrogen Oxides (NO2 etc.) Peroxyacetyl Nitrates (PAN) Tropospheric Ozone (O3) Volatile Organic Compounds Heavy Metals (Pb, Hg, Cd etc.) 88  Content of Photochemical Smog (cont.d) ❖ Photochemical smog is produced mainly by fuel and coal burning. Major contributors are SO2, CO and especially NO2. NO2 NO + O O + O2 O3 ❖ O3 is harmful to eyes, throat, respiratory system, agriculture etc. ❖ Incomplete combustion of carbon based fuels results in formation of volatile PAHs (they cause lung cancer). 89 Particulate Matter (PM or Aerosols) as Air Pollutant PMs are microscopic or sub-microscopic size, natural or anthropogenic, solid or liquid particles suspended in the air. PM10 : Inhalable particles with diameters that are 10 micrometers or smaller PM2.5 : Inhalable particles, with diameters that are 2.5 micrometers or smaller. They are adversely affecting ‘climate’ and ‘rain’ patterns in addition to being very harmful to human health through inhalation. They can get deep into your lungs and some may even get into your bloodstream. Smaller particles (PM2.5) pose the greatest risk to health. Common sources include power plants, industries, automobiles, construction sites, fields, fires. 90  Health Hazards of Photochemical Smog ❖In a historical example in 1952, Great Smoke killed about 4000 people in 4 days and another 8000 poeple died in the following months in London. ❖The Global Burden of Disease Study estimated that the worldwide impact of ‘outdoor’ air pollution [particulate matter (PM)2.5] was as many as 4.2 million deaths and 103 million disability-adjusted life years (DALYs) in 2015. ❖Exposure to ozone caused an additional 254 000 deaths and a loss of 4.1 million DALYs from chronic obstructive pulmonary disease in 2015. ❖In addition, high acute NO2 exposure levels are associated with a significant increase in cardiovascular mortality 91  Air Pollution Causes Premature Deaths PM is an air pollutant that causes cardiovascular and respiratory moralities, and it causes loss of life expectancy. if humans stop completely fossil fuel emissions, the global mean life expectancy would increase by 1.1 (0.9–1.2) years and 1.7 (1.4– 2.0) years It is estimated that PM2.5 exposure in India leads to about 570,000 (CI95: 320,000–730,000) premature mortalities in 2011 Just in Europe, 403000 people died because of PM 2.5 , 16000 because of tropospheric ozone, 72000 because of NO 2 in 2012. Research was conducted for 40 European countries.  3. Acid Rain ❖ The pH of natural rain is approximately 5.7. Acid rain decreases the pH to 2.4. Major source of the acidity in the rain is SO2 and NOx which is mainly coming from coal burning and other fossil-fuels. Globally an approximate of 150 million tonnes SO2/year was discharged into atmosphere. H2O + CO2 H2CO3 (Natural source for acidity) SO2 + OH HOSO2 HOSO2 + O2 HO2 + SO3 (Man-released sources) SO3 + H2O H2SO4 NO2 + OH HNO3 ❖ Acid rain was discovered in UK in 1882. However, it was first started to be studied in 1960. 93  Precautions and Results ❖ Reduction of SO2 emission was targeted in 1980 via Acid Deposition Act and in 1990 with a series of amendments. ❖ Total reduction of 10 million tons of SO2 was targeteded in 1990. The second phase of reduction was started in 2000. ❖ Since 1990, SO2 emission dropped as 40 % in USA, thus acid rain dropped 65 % in USA (70 % in Europe). 94  4. Global Climate Change- Warming and Dimming ❖ Global Warming is the rise in the average temperature of Earth’s atmosphere and oceans since the late 19th century and it is projected to continue. Increase in the greenhouse gases concentration especially in the CO2 is the major factor of warming. Since the beginning of the industrial revolution, CO2 concentration has raised from 280 ppm to 400 ppm today. CO2 mainly comes from fossil fuel burning (Coal 35%, Oil 36%, Natural gas 20%) Meanwhile, many other anthropogenic gases with much higher warming potential are also being released to the atmosphere (N20, CCl2F2, CF4, hexafluoroethane, SF6, etc.) 95 Livestock accounts for about 14.5% of ’Anthropogenic Greenhouse Gas Emisions’ estimated as 100-year CO2 equivalents GWP (Global Warming Potential) for CO2 is taken as exactly ‘1’ 96 97 ❖ Global Dimming is the gradual reduction in the amount of global direct irradiance at the Earth’s surface that was observed since 1950s. Today there is an average of 10% to 30% less solar radiation reaching Earth’s surface.  Artificial clouds are formed by aerosols which are industrial dust, mainly consisting of SO2 particulates. SO2 is mainly release by coal burning.  Pollution driven formation of artificial clouds leads to dangerous disruption in Earth’s atmospheric hydrological cycles, leading to drastic changes in weather patterns. One important example is the 1980’s subsaharan drought, killing more than a million people in Ethiopian region.  If pollutant aerosols are cleaned from atmosphere but the green house emissions continue than an increased effect of atmospheric warming occurs leading to extremely warm temperatures. One example is ‘European brightening’ that occured after limiting SO2 emissions in Europe, thousands of people died in France in summers of early 2000s. 98  Ocean Acidification An estimated 30–40% of the carbon dioxide from human activity released into the atmosphere dissolves into seas, lakes and rivers. Dissolved CO2 reacts with water to release carbonic acid (H2CO3), which increase H+ ion concentration in oceans by about 35%, decreasing pH from 8,25 to 8,14 between 1751 and 1996. Increased acidity is already being detrimental to aquatic life, especially for calcifying organisms (coccolithophores, corals, foraminifera, echinoderms, crustaceans and molluscs), as the pH goes down, consequently carbonate becomes undersaturated, then aquatic species that contain shells made of calcium carbonate become vulnerable to dissolution. Severe consequences of multi-faced alteration of natural environmental conditions: In its 2014 Living Planet Report, WWF has recently announced that Living Planet Index (LPI), which measures more than 10,000 representative populations of mammals, birds, reptiles, amphibians and fish, has declined by 52 per cent since 1970! (about 60% by 2017) Severe fall in insect populations are also well documented… 100 SPECİAL TOPIC: BIOCIDE POLLUTION: QACs and Antibiotic Resistance Benzalkonium Chlorides (BACs) Most widely used QACs Dodecylbenzyldimethyl Hexadecylbenzyldimethyl ammonium chloride ammonium chloride (C12BDMA-Cl) (C16BDMA-Cl) 340.0 g/mole 396.1 g/mole Tetradecylbenzyldimethyl ammonium chloride (C14BDMA-Cl) 368.0 g/mole Application of QACs Disinfectants Blend of chemicals that is applied on surfaces to destroy microorganisms 1. Hygiene 2. Disinfection of floors and surfaces 3. Disinfection of equipments 4. Disinfection of fabric Distribution of QACs in the Environment After Application (700,000 tons/year) 25% 75% Environment WWT Plants 0.05 mg/L 0.5 – 10 mg/L  At environmentally relevant concentrations microorganisms develop resistance to BACs EFFLUX PUMPS expel BACs from cells CATABOLIC ENZYMES detoxify BACs Tezel and Pavlostathis, 2012 Hegstad et al., 2010 THANK YOU 105  Natural Elemental Cycles / Anthropogenic Contributions The path atoms take from the living (biotic) to the non-living (abiotic) world and back again is called a ‘biogeochemical cycle’. Examples: Carbon cycle, Phorphorus cycle, Nitrogen cycle, Sulfur cycle… 106 END OF SEMESTER SPECIAL TOPICS: PESTICIDE CYCLE 107 Yellow colored micropollutants are used as pesticides 108 109 110 111