ERSTC-INDG 3730 Lecture 7 (23-24)-Chemical PDF

Indigenous People, Health and the Environment Indigenous people, health and chemicals (hazards) in the environment Lecture 7 1 1 Environmental Health Hazards/Benefits Model and Approach: Biological Hazards: e.g. bacteria, viruses, parasites and other pathogenic organisms Benefits: e.g. traditio...

Indigenous People, Health and the Environment Indigenous people, health and chemicals (hazards) in the environment Lecture 7 1 1 Environmental Health Hazards/Benefits Model and Approach: Biological Hazards: e.g. bacteria, viruses, parasites and other pathogenic organisms Benefits: e.g. traditional food species, traditional plants Chemical Hazards: e.g. toxic metals, air pollutants, solvents, pesticides Benefits: e.g. nutrients, anti-oxidants other critical elements of traditional plants, foods and other medicines Physical Hazards: e.g. radiation, temperature, sounds (noise) Benefits: e.g. temperature, sound (music) Mechanical Hazards: e.g. motor vehicle, home, agriculture, workplace injury Benefits: e.g. motor vehicle, traditional form of transportation, home, workplace (traditional and contemporary) benefits Psychosocial Hazards: e.g. stress, lifestyle disruption, effects of social change, marginalization, unemployment Benefits: e.g. stress-relief, balance, identity, cultural connection 2 2 1 Chemical Hazards “Those hazards posed by exposure to chemicals and chemical mixtures which can result in immediate or gradually acquired injury and disease” (Yassi et al., 2001) • • • Chemical hazards can cause injury, morbidity (disease, illness) and mortality (death) Some chemicals have high toxicity and a little amount can cause very significant damage Some chemicals act in ways that they have a delayed effect on health (induce change that takes a long time to appear, e.g. genotoxic effects) Examples of chemical hazards: PCBs, DDT, Mercury (Hg), Lead (Pb) 3 3 Chemical Benefits Those benefits posed by the exposure to chemicals and chemical mixtures which can result in immediate or gradually acquired health improvement or maintenance • Active compounds in traditional plants and medicines • Essential elements and vitamins that are needed for biological functioning • ‘Good’ fats coming from animal products (providing some protection against some chronic diseases like heart disease) Risks / Benefits are linked 4 4 2 What is a “chemical” ? “Any basic substance that is used in or produced by a reaction involving changes to atoms or molecules” (Cambridge online dictionary) 5 5 Common Environmental Hazards and Routes of Exposure Yassi et al., 2001 6 6 3 “Good Chemicals” in Traditional Plants Maori Traditional Uses of Manuka (Leptospermum scoparium) – Tea tree Plant Part Preparation Administration Action/Use Whole plant Whole plant Tea/strong infusion Decoction Internal internal Causes vomiting Increases urine Reduces fever Leaves Leaves/bark Steam inhalation Decoction Steam inhalation Inhaled Internal inhaled Treats head colds Stiff back/joints Reduces secretions Crushed bark Inner bark Infusion Infusion Internal internal Treats constipation Sedative for sleep Fresh sap Whole Internal Blood purifier Seed capsules Decoction Whole/chewed Powdered External External External Inflammations Alleviates colic Dry wounds/sores 7 7 “Good Chemicals” in Traditional Plants Creator’s Garden YouTube channel Joe Pitawanakwat https://www.youtube.com/c/JoePitawanakwat/videos Sweet fern: https://www.youtube.com/watch?v=MhHm7H-mFFU 8 8 4 “Bad Chemicals” Silent Spring (1962) • Author: Rachel Carson • Detrimental effects of pesticides on the environment (e.g. birds) • Predicted far reaching impacts on environment and humans • Criticized public acceptance of chemical approach to control • Argued for biological control mechanisms Mainly due to Silent Spring, over forty bills had been introduced to regulate pesticide use in various states by the end of 1962 9 9 Paradigm Shift Before WW II Dilution Paradigm After WW II Boomerang Paradigm 10 10 5 “Dilution is the solution” - or is it ? 11 11 Contributing Factors for Shift 1956-60 Minamata Disease “loss of Placental Barrier” 1961 Thalidomide “loss of Privileged Fetus” 1960-70 Diethylstilbestrol (DES) – synthetic estrogen “loss of immediate disease effect” 1990s Dichlorodiphenyltrichloroethane (DDT) Endocrine disruption-loss of absolute receptor 12 12 6 Chemical Hazards A few #s: • At least 10,000,000 chemicals have been synthesized since 1900 • there are at least 75,000 chemicals in commercial use • each year about 1,000 new synthetic chemicals are introduced into the marketplace • the average body contains about 500 synthetic organic chemicals - which did not exist in 1920 whose health effects are mostly unknown Yassi et al., 2001 13 13 Common releases to the environment Hazardous waste injection well Pesticides Coal strip mine runoff De-icing road salt Buried gasoline and solvent tank Pumping well Cesspool septic tank Gasoline station Water pumping well Waste lagoon Landfill Sewer Leakage from faulty casing Accidental spills c Un Co on n fi fin ne ed fr w esh s a hw re df a te te r q ra aq u if u if er er Discharge Confined aquifer Groundwater flow 14 14 7 Everyday Exposure Chloroform Para-dichlorobenzene Tetrachloroethylene 1, 1, 1Trichloroethane Formaldehyde Benzo-a -pyrene Nitrogen Oxides Styrene Tobacco Smoke Asbestos Carbon Monoxide Methylene Chloride Radon-222 15 15 Toxic Chemicals – Grouping by Actions 1. Allergens - Substances that activate the immune system. – Antigens - Allergens that are recognized as foreign by white blood cells and stimulate the production of specific antibodies. • Other allergens act indirectly by binding to other materials so they become antigenic 16 16 8 Toxic Chemicals – Grouping by Actions 2. Neurotoxins - Metabolic poisons that specifically attack nerve cells. – Different types act in different ways. • Heavy Metals kill nerve cells. • Anesthetics and Chlorinated Hydrocarbons disrupt nerve cell membranes. • Organophosphates and Carbamates inhibit signal transmission between nerve cells. 17 17 Toxic Chemicals – Grouping by Actions 3. Mutagens - Agents that damage or alter genetic material. • Nicotine – Lung cancer 4. Teratogens - Specifically cause abnormalities during embryonic growth and development. • Alcohol - Fetal Alcohol Syndrome 5. Carcinogens - Substances that cause cancer. • Chemicals in cigarette smoke, Formaldehyde – nasopharyngeal cancer 18 18 9 Inorganic Vs Organic Contaminants Grouping by Properties Fundamental Difference Inorganic - naturally occurring elements • contaminants such as Pb or Ni can’t be broken down into other compounds • Cannot be created nor destroyed, only transformed and redistributed Organic – predominantly human-made • contaminants such as solvents or pesticides can be broken down (degraded) into other compounds – the other compounds can be less or more toxic than the parent compound 19 19 Inorganic chemicals • Metals and metalloids – Characteristic lustre in elemental state – Malleable and ductile – Forming positively charged ions (cations) – Higher melting pt and boiling pt than non-metals (i.e. solid at normal temperature and pressure) – Higher in density than non-metals – Usually good conductors of heat and electricity – Naturally occuring 20 20 10 Sources of metals... Natural sources: • forest fires • volcanic eruptions • natural weathering of rocks (role of acid rain) Anthropogenic sources : • mining • smelting • agriculture 21 21 Trace elements – toxic or essential ? deficient toxic essential health non-essential optimal range concentration tolerable range “The dose makes the poison” 22 22 11 Health Stimulation Biological Response to Metals Macronutrient e.g. lipids, carbohydrates, proteins Inhibition Concentration / Dose Micronutrient (microminerals and vitamins) e.g. iron Nonessential toxic element e.g. Methylmercury 23 23 Organic Chemicals • All contain C • Nearly all contain H and have at least one C-H bond • Non-essential • Many are lipophilic – “fat loving/soluble” • most man-made chemical are viewed as “contaminants” when released into the environment 24 24 12 The Dirty Dozen: Pesticides: Chlordane DDT (dichloro-diphenyl-trichloroethane) dieldrin endrin heptachlor HBC (hexachlorobenzene) mirex aldrin toxaphene Industrial chemicals: PCBs (polychlorinated biphenyls) 25 By-products: Dioxin (polychlorinated-dibenzo-p-dioxins) Furans (polychlorinated-dibenzofurans) 25 PCBs • Added to mineral or silicone oils to reduce flammability and wear – Capacitors and transformers – Hydraulic fluids • 209 congeners • <90 congeners in environmental samples • IUPAC nomenclature for each congener 26 26 13 PCBs were first manufactured in 1929 Attention began to focus on potential hazards linked to the use and disposal of PCBs, when the presence of PCBs was detected in the Great Lakes for the first time in 1966. By 1977, concern over the impact of PCBs on the environment led to a North American ban on manufacturing and importing PCBs. The ban did not cover PCBs that were already in use in electrical applications. These are being phased out now, and the federal government has set strict regulations for the handling, storage and disposal of PCBs. 27 http://www.hc-sc.gc.ca/iyh-vsv/environ/pcb-bpc_e.html 27 Sources • Previous releases of PCBs into the environment – Landfills – Environmental “sinks” (e.g. sediments) – Atmospheric deposition (global circulation) • Accidental releases of PCBs in storage or during destruction 28 28 14 Biproducts of Incineration • Sources: – Low temperature municipal incinerators – Coal-fired electrical plants • Primarily highly chlorinated congeners formed (hexa-, hepta- & octa-CDD/CDFs); varying toxicity 29 29 Pathways Common releases to the environment Hazardous waste injection well Pesticides Coal strip mine runoff De-icing road salt Buried gasoline and solvent tank Pumping well Cesspool septic tank Gasoline station Water pumping well Waste lagoon Landfill Sewer Leakage from faulty casing Accidental spills c Un Co on n fi fin ne ed fr w esh s a hw re df a te te r q ra aq u if u if er er Discharge Confined aquifer Groundwater flow 30 30 15 Chemicals and Indigenous Peoples Around the World Contaminants ØOrganic Øorganochlorines ØDDT, PCBs etc ØInorganic Øheavy metals ØPb, Cd, Hg 31 31 Distribution Application / Release -spray, dump,etc -mining, smelting, burning etc Volatilization -transfer from liquid and solid phase to gas or vapour Transport -dominant air and water currents Deposition -wet -dry 32 32 16 33 33 Bioaccumulation • contaminant concentration in organism is higher than in the surrounding environmental compartment • increases over time 34 34 17 Biomagnification DDT in fish-eating birds (ospreys) 25 ppm DDT in large fish (needle fish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm DDT in water 0.000003 ppm, Or 3 ppt • occurs for mostly for very lipophilic contaminants (= not for trace elements) • occurs only when contaminant uptake is from diet 35 35 Environmental Fate and Interactions of Organic Compounds The biological / ecological impact of a contaminant is influenced by its chemical properties: 1. Accumulation: Bioconcentration / biomagnification 2. Persistence: Resistance to breakdown 3. Biological reactivity with biological molecules (e.g. toxicity: many different mechanisms of action) 36 36 18 37 37 Routes - Exposure and Elimination Biotransformation or Detoxification = physiological process to reduce toxicity of contaminants (e.g. polar bears can metabolize some PCB congeners) Bioactivation = biochemical process that increases toxicity of a substance (e.g. ‘prodrugs’ such as prednisone, bioactivated by the liver) Figure 2.2 Routes of absorption, distribution, and excretion of potentially toxic substances. Dotted lines indicate materials potentially useful for biological monitoring. Yassi et al., 2001 38 38 19 Patterns of Health Effects by Toxic Substances 1. Systemic toxicity – toxic effects that result from absorption of a chemical and its spread to different body systems. E.g. sometimes fatal poisoning via contact with organophosphate pesticides; inhalation of organic solvents A. Neurotoxicity – most toxic substances act on the central or peripheral nervous system. Functional or organic changes in neurotransmitters can cause impaired function of paralysis. E.g exposure to organophosphates, chlorinated organic compounds, some metals. B. Immunotoxicity – impaired immune defense function ; chemical exposure can result in increase susceptibility to viral illnesses (influenza or cold); impaired immune reactions and development of allergy (alterations of body components and biological function by contaminant exposure, immune system then attacks them with antibodies and triggers inflamation, tissue breakdown etc) 39 39 Patterns of Possible Health Effects by Toxic Substances 2. Organ specific toxicity – Certain chemicals have a target organ specificity, because of biotransformation or bioconcentration. A. Liver toxicity – Most chemicals are metabolized in the liver, therefore it is a target organ. E.g. Organic solvents and certain trace metals (copper, cadmium) may damage liver – fatty changes, necrosis, fibrosis, alteration of structure B. Kidney toxicity – Many xenobiotics are removed by the kidney while essential elements are reabsorbed. E.g. mercury, cadmium, lead C. Skin toxicity – Skin rash in response to exposure to a chemical is not uncommon. Some are specific to the chemical, most are not. 40 40 20 Chemical Exposure and Unique Situation of Arctic Indigenous Peoples “Factors influencing exposure” • • • • • • • • Continued production and use of hazardous chemicals in the world Atmospheric and oceanic transport around the globe Grasshopper effect (movement towards cold climates) Final deposition in cold areas Bioaccumulation in wildlife over time Biomagnification up the food chain (particularly organic contaminants) Indigenous health, diet, tradition, livelihood tied to land Indigenous consumption of higher level, fat rich (fatty) predator species = disproportionately higher levels of exposure to contaminants from ‘far away’ in Arctic Indigenous peoples 41 41 Case Example Inorganic (Metals) Contaminants in Traditional Foods of Arctic Indigenous People Readings and Resources. Donaldson et al., 2010 Sections 1, 2, 8 and 9 42 42 21 Variety and Level of Consumption • Regional diversity • Strong reliance on food from land, sea, water 43 43 • Important components of health, identity, culture, local economy 44 44 22 Inorganics • Not a single contaminant • In some cases over ‘recommended limits’ • Variability between regions and within regions • Variability between cultural groups 45 45 Potential Negative Impacts of Exposure to Contaminants via Traditional Food Consumption POPs (Organics) PCB, DDT, chlordane, toxaphene • Neurodevelopmental – cognitive and neuromotor development (fine motor movement, learning ability) • Immune System Functioning – otitis media (inner ear infections in children) • Carcinogenic – breast and other cancers • Genotoxic – sex ratio Heavy Metals (Inorganics) MeHg, Pb, Cd • Neurodevelopment – cognitive and neuromotor development • Organ function – liver and kidney • Carcinogenic – liver, prostate • Premature mortality 46 46 23 « Good » Chemicals in Traditional Foods Consumption Among Inuit Women in Nunavik 250" 200" % of RNI 150" 18-39 100" 40 & over 50" 0" Protein" Vitamin"D" Iron" Phosphorus" Nutrient Selenium" Zinc" 47 47 « Good » Chemicals in Traditional Foods and Biological Benefits Rate / 100,000 persons per year Mortality rate Plasma concentrations EPA+DHA 160 8 140 7 120 6 100 5 80 4 60 3 40 2 20 1 0 0 Québécois James Bay Cree Nunavik Inuit Concentrations (% of total fatty acids) Omega-3 Fatty Acid and Heart Disease Other fishes 20% Arctic Char 39% Wildfowl 1% Marine Mammal fat 31% Marine Mammal meat 9% 48 48 24 Chemical Benefits of Traditional Food Consumption • Lipids – fish and m. mammal tissues high in EPA and DHA omega-3 fatty acids – linked to low rates of ischemic heart disease, inflamatory disease (Dyerberg etal., 1975; Yamori et al., 1995) – protection against high blood pressure, diabetes, and certain cancers (breast, colon, prostate) – brain development on fetus, birth wt, all aided by omega-3 fatty acids • Minerals – majority of essential minerals for all groups comes from country foods – nutrient density (nutrient per caloric intake) greater for Arctic men and women in country foods portion of diet (Kuhnlein, 1995; Kuhnlein et al., 1995,1996) – high selenium concentrations in marine species - anticarcinogen, antagonistic effect on MeHg toxicity (experimentally) – Zn, Fe, Ca, Se, Co, Mn, B6, ascorbic acid and protein interact with Cd – Zn, Fe, Ca, Se, Co, Cr, interact with toxicity of lead 49 49 Chemical Benefits of Country Food Consumption • Vitamins and Protein – low Vit A and Ca intakes, B12 and pantothenic acid, niacin, riboflavin, thiamin intakes good – clinical evidence of deficiencies not seen in Arctic populations – country foods provide enough protein to reach RNI, over 80% of protein requirements came from country foods in Sanikiluaq (Wein, 1995) ALSO • Social and Cultural Benefits – not to be underestimated as country food is central to social health of many individuals and communties and dietary shifts have been associated with social, mental and physical pathologies elsewhere – country foods reported to embody, define, maintain and continue culture, tradition and identity of Aboriginal peoples – provide basis for active traditional lifestyle (less sedentary) • Economic importance – estimated value of country foods of $10,000 per household in NWT (replacement costs by equal weight in market meats) (Usher and 50 Wenzel, 1989) 50 25 • Exposure to methylmercury via fish consumption among Seminole and Chippewa people in the US • MeHg is neurotoxic • ‘at-risk’ for increased mercury exposure • Recognize the importance of fish consumption for Indigenous identity and culture; impacts on cultural relationship with the environment Readings and Resources. Roe, 2003. Fishing for Identity 51 51 Vulnerability of Indigenous Peoples to Chemicals in the Environment V=f(E,A) Exposure related to: • Location of residence and deposition of contaminants (e.g. Arctic, Grassy Narrows, Akwasasne) • Relationship between people and environment - diet, socioeconomy, culture and identity, physical activity, etc. • Level of consumption of traditional/country foods (pathway of exposure) Adaptive capacity: • Alternate pathways for replacement of same benefits • Barriers (economic, social, cultural) to accessing benefits through other pathways • Control over exposure (controlling source of exposure) • Awareness / information of the risk 52 52 26 “Good Chemicals” in Traditional Plants Creator’s Garden YouTube channel Joe Pitawanakwat https://www.youtube.com/c/JoePitawanakwat/videos Sweet fern: https://www.youtube.com/watch?v=MhHm7H-mFFU 53 53 Supplementary Reading Dewailly et al., 2000. Susceptibility to infections and immune status in Inuit infants exposed to organochlorines, EHP Donaldson et al., 2010. Review: Environmental contaminants and human health in the Canadian Arctic, Science of the Total Environment (Sections 1, 2, 8 and 9) Juric et al. 2017. Total diet study and probabilistic risk assessment of dietary mercury exposure among First Nations, Env Research Newman et al. 2016. Cognitive functioning of Akwasasne Mohawk adolescents exposed to PCBs, Journal of Indigenous Research. Philibert et al., 2022. Past mercury exposure and current symptoms of nervous system dysfunction in adults of a First Nation community (Canada), Environmental Health Philibert et al., 2020. Mercury exposure and premature mortality in the Grassy Narrows First Nation community: a retrospective longitudinal study, The Lancet Roe, 2003. Fishing for Identity: Mercury contamination and fish consumption among Indigenous groups in the United States, Bull Sci Tech Soc. Yassi et al., 2000. Basic Environmental Health. pgs 80-91 54 54 27 Reminders • Visit with Beedahbin Peltier – next week; please come prepared to listen and engage • Video seminar associated with today’s lecture – posted in the Seminar Folder – ‘Scars of Mercury’ – View the film and respond to the questions by Due Nov 28th • Assignment #2 – Due Nov 21st – Studies Credit Students – Register topic with Jacob or Chris asap ([email protected]) 55 55 Video Seminar for Today’s Lecture (worth 6%) Watch online film: ‘Scars of mercury’ about mercury at Asubpeeschoseewagong First Nation (Grassy Narrows First Nation) https://www.cultureunplugged.com/documentary/watch-online/festival/play/6412/TheScars-Of-Mercury Answer questions in the Seminar folder in Blackboard and submit your responses as a word document attachment to the Seminar folder by Nov 28th For an update on the issue see: https://www.cbc.ca/news/canada/thunder-bay/grassy-narrows-mercury-poisoining-study1.6387194#:~:text=It%20is%20estimated%2090%20per,the%20food%20chain%20decades%20ago. (August 2022 - New study shows lasting effects of mercury poisoning in 90% of residents) https://www.cbc.ca/news/canada/thunder-bay/grassy-narrows-mercury-care-facility-ottawa-funding-1.6117975 (July 2021 – Money provided for new care facility for those impacted by mercury poisoning) https://www.aptnnews.ca/national-news/grassy-narrows-signs-agreement-for-new-mercury-treatment-facility/ (April 2020 – Grassy Narrows signs agreement for new mercury treatment facility) https://www.cbc.ca/news/canada/thunder-bay/grassy-narrows-ottawa-no-deal-1.5278233 (Sept 2019 – no agreement on mercury care centre for Grassy Narrows) https://www.cbc.ca/news/canada/thunder-bay/grassy-narrows-health-report-release-1.4675942 completed and results show long term effects) (May 2018 – new health report https://globalnews.ca/news/4498956/ontario-government-to-increase-mercury-disability-payments-to-affected-first-nations/ (Sept 2018 Increase in disability payments by Provincial Gov’t) https://globalnews.ca/news/4569538/supreme-court-grassy-narrows-mercury/ (Oct 18 2018 – Supreme Court to hear case on clean up) 56 56 28