Chapter 18 Environmental Health PDF

Chapter 18 Environmental Health Slides prepared by: Dave Kato MacEwan University Learning Objectives Explain how population growth affects Earth’s environment and contributes to pollution and climate change Discuss the causes and effects of air and water pollution and describe strategies th...

Chapter 18 Environmental Health Slides prepared by: Dave Kato MacEwan University Learning Objectives Explain how population growth affects Earth’s environment and contributes to pollution and climate change Discuss the causes and effects of air and water pollution and describe strategies the people can take to protect these resources Discuss the issue of solid waste disposal and the impact it has on the environment and on human health Identify key sources of chemical and radiation pollution and discuss methods of preventing such pollution Explain how energy use affects the environment and describes steps everyone can take to use energy more efficiently Environmental Health Defined Environmental Health1 Grew out of efforts to control communicable diseases Increasing awareness of the relationship between human activity and its impact on the planet Specific insects and rodents were found to carry microorganisms causing disease – attempt to control these vectors Recognized that pathogens could be carried in sewage and garbage Led to garbage collection, filtration and chlorination of water and food inspection Environmental Health2 Changed the health profile in Canada and the developed world People rarely contract cholera, typhoid fever, plague, diphtheria or other diseases that killed large numbers of people Canada has a complex system working behind the scenes Every time the system is disrupted danger occurs Restoration of basic health services becomes paramount for human survival Traveling beyond our boundaries reminds us of the importance of the basics We recognize that environmental pollutants contribute to chronic disease in addition to infectious disease Technological advances have had a negative impact on the health of the planet and human health Population Growth and Control  How Many People Can the World Hold? Suggested that the Earth’s carrying capacity has been exceeded Food Better food distribution is needed in the future – change in diet may be needed Available land and water Rural populations rely on trees, soil and water and these are being depleted Habitat destruction and species extinction Energy Most of the world’s energy comes from non-renewable resources Will need greater energy efficiency Minimum acceptable standard of living Mass media has exposed the world to the North American lifestyle Raised expectations  Factors That Contribute to Population Growth Populations trends are difficult to influence and manage Fertility rates Developed countries have reductions in fertility due to contraception while undeveloped countries have fertility rates sustaining population growth Families have enough children to work for the household and care for parents in old age Lack of family planning resources More than half of the world’s population do not use any form of family planning Lower death rates Higher rates in developing countries but have decreased in public health measures and improved medical care Population management must change the condition of people’s lives Remove the pressure to have large families Air Quality and Pollution Air Quality and Smog The air quality health index (AQHI) is used to determine potential health risk Calculated on the risks of the mixture of: Nitrogen Dioxide (NO2) Particulate matter Ground level ozone (O3) The higher the AQHI the greater the associated health danger +7 or above is considered high Smog was first used in London in the early 1900’s to describe smoke and fog Today smog is a mixture of pollutants with ground level ozone being the key ingredient Heavy motor vehicle traffic, high heat and sunny weather Greenhouse Effect and Climate Change1 Temperature of the earth depends on the balance of energy absorbed and radiated back to space Key components of temperature regulation are: Carbon dioxide Water vapour Methane Other greenhouse gases Greenhouse gases are so names as they act like panes of glass in a greenhouse Traps some of the infrared radiation and re-radiate it back to earth Needed to keep the Earth more hospitable for all life forms Figure 18.2 The Greenhouse Effect Greenhouse Effect and Climate Change2 There is consensus that human activity is causing global warming or climate change Climate change – long term shift in weather conditions Global warming – an increase in the Earth’s atmospheric temperature Serious weather events: More frequent flooding Extreme heat Extreme cold weather events Greenhouse Effect and Climate Change3 Combustion of fossil fuels Levels of CO2 have increased dramatically in recent decades Ice core samples suggest CO2 is 40% higher than in the last 800,000 years Deforestation sends CO2 into the atmosphere and destroys the trees that covert CO2 into O2 Canada ranks in the top three countries to emit more than double the global average of greenhouse gases Years 2016 and 2020 were the warmest on record 2017 was third Since 2022 the past seven years have been the warmest recorded Table 18.1 Sources of Greenhouse Gases Greenhouse Gas Sources Carbon dioxide Fossil fuel and wood burning, factory emissions, car exhaust, deforestation Chlorofluorocarbons (CFCs) Refrigeration and air-conditioning, aerosols, foam products, solvents Methane Cattle, wetlands, rice paddies, landfills, gas leaks, coal and gas industries Nitrous oxide Fertilizers, soil cultivation, deforestation, animal feedlots and wastes Ozone and other trace gases Photochemical reactions, car exhaust, power plant emissions, solvents Figure 18.3 Trend in Annual Mean Temperature Source: NASA, Goddard Institute for Space Studies. (2022). Global Annual Mean Surface Temperature Change. Retrieved March 19, 2022, from https://data.giss.nasa.gov/gistemp/graphs_v4/. Greenhouse Effect and Climate Change4 Growing agreement that the temperatures will continue to rise High latitudes will warm faster due to melting ice Land areas will warm faster than the ocean Possible consequences of continued warming include: Increased rainfall in some areas and drought in others Increased mortality from heat stress, urban air pollution and tropical diseases Death from extreme weather events – tornadoes, hurricanes A poleward shift of 150 – 500km in the location of vegetation zones Increasing and drastic melting of the polar ice caps Greenhouse Effect and Climate Change5 March 2022 – a report released by the Intergovernmental Panel on Climate Change suggested a 1.1°C above pre-industrial levels Level of warming is nearing 1.5°C to 2.0°C Warns of more serious and far-reaching impacts if greenhouse gases are not reduced by 50% by the end of the decade The Paris Agreement Three billion people live in environments that are vulnerable to the impacts of climate change Felt most acutely by the poorest and underdeveloped nations Reduced food and water security Irreversible loss of marine ecosystems Changes suggest modification of agricultural practices, enhancement of flood protection and diversification of tree species Thinning of the Ozone1 The ozone is an invisible layer in the atmosphere Shields the earth from ultraviolet rays (UV) Since the mid-1980’s scientists have observed a seasonal appearance and growth of a hole over Antarctica Layer is destroyed by chlorofluorocarbons (CFC’s) used as coolants in refrigerators, air conditioners and some aerosol sprays Banned in Canada in the late 1970’s Use of CFC’s worldwide has declined once the danger to the ozone was recognized When they rise in the atmosphere winds carry them to the polar regions The polar vortex in Antarctica keeps air from mixing allowing CFC’s to combine with ice crystals to release chlorine which in turn destroys the ozone When the vortex weakens in the summer the ozone is replenished Thinning of the Ozone2 Northern hemisphere ozone has depleted by about 10% Potential effects include increased skin cancer, wrinkling and aging of the skin, cataracts and blindness and a reduced immune response May interfere with photosynthesis and cause lower crop yields May also kill phytoplankton and krill Heat generated may cause changes in the stratospheric winds The ozone layer is not expected to be “repaired” until 2070 2017 NASA reported the hole is the smallest since 1988 Shrinkage due more to natural variability rather than human activity Energy use and Air Pollution1 Environmental Threats of Extreme Energy Sources Extreme energy sources – fossil fuels that are hard to access Deep water oil rigs, tar sands and fracking are examples Pipelines across wildlife habitats to shipping terminals on the coast Fracking uses pressurized mixes of fluids to create cracks in the rock releasing natural gas Several first nation communities have protested the exploration on native lands Renewable energy Are sources that are naturally replenished e.g. wind and sunlight, wave and geothermal Sustainable development means meeting the needs of the society today without compromising the ability of future generations to meet their needs Energy use and Air Pollution2 Renewable resources continued Wind power – energy of the wind to turn turbine blades Solar power – photo energy is converted to electrical energy Geothermal power taps the heat in the earth's core Hydroelectricity is produced when flowing water is used to turn the blades of a turbine Biomasses plant material including trees when burned produce energy. Plants are produced and harvested sustainably are considered a renewable source of energy Biofuels are those fuels based on natural materials either alcohol or oil Canada is recognized as a global leader in the production and use of renewable energy Alternative Fuels The Government of Canada and some provincial governments have encouraged the development and use of ethanol Ethanol reduces the amount of oil to produce gasoline which in turn reduces greenhouse gases Another source of alternative fuel is ethanol flex-fuel 85% ethanol and 15% gasoline (E85) Controversy exists as to the production of ethanol, however ethanol made from sugar cane and other woody crop plant material maybe far more energy efficient Potential drawback is the version of corn crops from food supply to produce fuel United nations has called for a moratorium until non-food sources of alternative fuels can be developed Hybrid and Electric Vehicles Hybrid vehicles uses two or more distinct power sources to propel the vehicle Typically a combination of onboard energy storage such as batteries and an internal combustion engine with an electric motor Provides greater fuel economy intends to run with less noise Downside is that they tend to cost a few thousand dollars more Second generation of all electric vehicles have been introduced to consumer markets Requires the development of charging stations and better battery development Indoor Air Quality Your home may harbor potentially dangerous pollutants some of which have been linked to cancer Environmental tobacco smoke Carbon monoxide and other combustion by-products Volatile organic compounds Biological pollutants Indoor mould Preventing Air Pollution1 The following are some guidelines to help reduce air pollution: Cut back on driving Keep your car tuned up and well maintained Buy energy efficient appliances and use them only as necessary Replace incandescent bulbs with LED and compact fluorescent bulbs Make sure your home is well insulated with ozone safe agents Plant and care for trees in your own yard and neighborhood Preventing Air Pollution2 The following are some guidelines to help reduce air pollution continued: Check with waste haulers or local and government before disposing of refrigerators air conditioners or humidifiers Keep your house adequately ventilated Keep paints cleaning agents and other chemical products tightly sealed in their original containers Don't smoke and don't allow others to smoke in your room apartment or home Clean and inspect chimneys furnaces and other appliances regularly Water Quality and Pollution Water Contamination and Treatment Most cities rely in part by wells that tap local groundwater, but may be necessary to tap lakes and rivers to supplement water demand Surface water is most likely to be contaminated and therefore must be purified before piped into the community The water is subjected to various physical and chemical processes Fluoridation has been used to reduce tooth decay by 25% for the last 75 years Although most areas of Canada have dependable, clean water sources, many Indigenous communities do not As of January 2022, 39 long-term water advisories were in effect in First Nations communities Water Shortages Shortages are becoming a concern in many areas of the world Less than 1% of the world's freshwater is readily accessible for direct human use Approximately 2.1 billion people do not have access to safe readily available drinking water 4.5 billion do not have access to safe sanitation Canada is considered a water rich country Canada does have some shortage issues in some area Globally, some examples of shortages include the Aral Sea in Kazakhstan and Uzbekistan – 2/3 of the water has been drained for human use The Yellow River in China ran dry in 1972 for the first time in a 3000-year history Sewage1 The ancient Romans had been credited for the development of sanitation and sewage This was last during the industrial revolution in Europe Cesspits in open sewers were constructed in urban centres but became overrun Mid 19th century saw an increase in serious diseases such as typhoid, cholera and hepatitis As plumbing moved indoors, sewage disposal became far more complicated Septic systems in in rural areas: Although usually safe, older septic systems have failed and are contaminating the environment Sewage2 Different approaches became necessary as urban areas developed Most cities have sewage treatment systems that separate fecal matter from water in huge tanks Once treated and biologically safe it's released back to the environment Sludge is left behind is often contaminated with heavy metals treated as hazardous waste In some cases, was used as fertilizers but the heavy metals got into the environment In addition to heavy metals, contamination from polychlorinated biphenyls (PCBs) have also been linked with long term health consequences Removal of heavy metals and PBCs is still developing an incredibly expensive Sewage3 Or a toilet flushing behavior in Canada has become a burden for wastewater managers and taxpayers Clogged sewers and fatbergs Non biodegradable products such as baby wipes, makeup remover pads, and other personal care wipes have created these clogs Officials are currently advocating for the development of a standard definition for flushable items Protecting the Water Supply Reducing your own water use you can help preserve the valuable water supply and reduce your water bill Take showers not baths Install faucet aerators and water efficient shower heads Purchase and use a water saving toilet Fix any leaky faucets in the home Don't pour toxic materials such as cleaning solvents down the drain Don't pour old medicines down the drain or flush them down the toilet Solid Waste Pollution Solid Waste What’s in our garbage? The average Canadian generates more than 720 kilograms of household waste every year Single biggest component is organic waste from kitchens in yards followed by paper products A small percentage of the solid waste is toxic such as dispose of electronics in both household and commercial waste Burning as opposed to burial reduces the bulk of solid waste but may release hazardous material into the air The Love Canal travesty identified major problems with handling industrial waste In the early 70s people had to move out of their houses U2 a significant increase in birth defects and cancers Huge costs were incurred to relocate these families Figure 18.4 Components of Municipal Solid Waste Generated by Canadians Before Recycling Disposing of Solid Waste Most common way to dispose of waste is to bury it in a sanitary landfill Site is thoroughly study to ensure it's not near groundwater, streams or other source of water that can be contaminated In contrast to garbage dumps of previous generations, landfills are now designed with protective liners to control leachate In some instances, landfills have been converted to parks Some major disadvantages include: Waste contains chemicals that should not be released into the environment Despite precautions contaminants sometimes leach into the surrounding soil and groundwater Expensive and requires huge amounts of space Figure 18.5 A Sanitary Landfill Biodegradability Biodegradation is the process in which organic substances are broken down to naturally by living organisms can be done aerobically or anaerobicly The term biodegradable being certain products can breakdown naturally, safely and quickly into raw materials of nature Table 18.2 Biodegrading Times of Different Objects Item Time Required to Biodegrade Banana peel 2–10 days Paper 2–5 months Rope 3–14 months Orange peel 6 months Wool sock 1–5 years Cigarette butt 1–12 years Plastic-coated milk carton 5 years Aluminum can 80–100 years Plastic six-pack holder ring 450 years Glass bottle 1 million years Plastic bottle Forever Recycling In recycling, waste materials are collected and used as raw materials in the production of new products paper can be recycled into new paper products or an old bicycle frame can be melted down and used in the creation of new appliances Recycling is good for two reasons it puts back unwanted objects back to good use reduces the amount of solid waste sitting in landfills Irrespective of our recycling capability, we should focus on reducing and reusing Technology: e-Waste A more recent problem has emerged, the discarding of old cell phones, tablets, computers, televisions and other electronic devices 2017, Canadian scrapped 640,000 tonnes of electronic waste Is the fastest growing portion of the waste stream How's your days because of the amount of lead, mercury and other heavy metals Most components can be recycled and reused Look for a green program that is certified by e-Stewards Reducing Solid Waste By reducing consumption, recycling more and throwing away less we can conserve landfill space Purchase products with the least amount of packaging Buy recycled or recyclable products avoid using foam or paper cups Use glass jars and plastic recyclable containers Recycle your glass cans paper and other recyclables Impossible, avoid printing all your lecture, study or lab notes Do not throw away electronic items, batteries or fluorescent lights into the trash Start a compost pile for organic garbage Chemical Pollution and Hazardous Waste Asbestos Widely used in insulation until the 1980’s Asbestos fibres released into the air caused asbestosis and lung cancer Areas most likely to be found are insulations around: Water and steam pipes Vinyl flooring Ceiling insulation Roofing an siding Fireproof board 2018 Canada passed regulations under the Environmental Protection act banning asbestos containing products Lead1 Lead poisoning is not like it was in the past Children under the age of three were most susceptible to the effects of lead Tends to be associated with lower income households and immigrants Lead can damage the central nervous system causing mental disorders and digestive problems Neurological damage can be permanent Lead2 Long term exposure to lead may cause kidney problems and a build up in bones may cause osteoporosis Lead based paints were the chief culprit in lead poisoning Lead was eliminated in 1991 – Canadian regulations eliminated lead in 1978 Older homes with pipes that may contain lead should let water run due to leaching of lead from the pipes Advised not to use hot water for drinking or cooking for the same reason Pesticides Used primarily for two purposes: Prevent spread of insect borne disease Maximize food production The pesticide DDT was effective in controlling insect borne disease Got into the food chain and caused disruption to the life cycles of birds fish and reptiles Larger animals eat the smaller ones – bioaccumulation and biomagnification DDT although effective, was banned in 1985 due to the potential effects on wildlife and humans Concerns remain about long term exposure especially for children Mercury Mercury is a naturally occurring metal affecting the nervous system causing damage to the: Brain Kidneys Gastrointestinal tract Increase blood pressure and heart attack risk May cause cancer Mercury slows fetal neural development Mercury persists in the environment and like pesticides is bioaccumulative Other Chemical Pollutants Hazardous waste is found in the home and should be disposed of properly Old antifreeze Transmission fluid Old paint and paint thinner Insecticides Batteries Computer components Household cleaners containing NaOH (sodium hydroxide) Preventing Chemical Pollution Reduce chemical pollution by: Reading labels – buy the least toxic ones Choose non-toxic, non-petrochemical cleansers, disinfectants and cleansers Dispose of hazardous waste properly Buy organic produce If you must use pesticides or toxic chemicals, do not let children or pets get at them If having your house fumigated, use a reputable exterminator – keep children and pets away for as long as possible Radiation Pollution Radiation comes in different forms Ultraviolet radiation Microwaves X-rays Sources include: The sun Uranium Nuclear weapons Other sources of concern: Gamma rays produced by nuclear weapons, nuclear energy plants and radon gas Can cause chromosome damage Figure 18.6 Electromagnetic Radiation Nuclear Weapons and Nuclear Energy Nuclear weapons are serious health risk to the entire world Use of these weapons would result in the deaths of millions of people Nuclear power plants also pose a major problem Touted as a safe source of energy Human error is the biggest challenge to using this energy source E.g. Chernobyl in Ukraine Earthquakes in Japan Disposal of nuclear waste is not infallible Medical Uses of Radiation An area of concern are X-rays that are routinely used to diagnose injury and illness in patients X-rays are cumulative – associated with an increased risk of cancer No exposure is safe Adults have less risk of radiation-induced health conditions After age 60, X-rays are no longer a problem Naturally Occurring “Background” Radiation The average person is exposed to 3 millisieverts of natural radiation Cosmic radiation coming from outer space The dose depends where you live, higher altitudes receive 50% more “background” radiation than those at sea level Radiation in the Home and Workplace Concern has been raised about the radiation emitted from common devices such as: Microwave ovens Computer monitors High-voltage power lines Cell phones Safe absorption rate (SAR) is a measure of the quantity of radio frequency energy absorbed by the body This issue is still under investigation Radon Naturally occurring radioactive gas found in soil, rocks and building material When inhaled cling to the lungs and bomb sensitive tissues with radiation Radon can enter the home in cracks, dirt floors and other openings in the structure Avoiding Radiation Only get X-rays when needed Don’t have CAT scans as a routine evaluation Follow Health Canada’s recommendations for radon testing Use sunscreen to protect yourself from the sun’s UV radiation Noise Pollution1 Loud and persistent noise in the environment Focus on two areas, hearing loss and stress Prolonged exposure to sound about 80-85db can cause permanent hearing loss Regular exposure of 1 minute at 100db can cause hearing loss Children may suffer damage to their hearing at lower noise levels Common areas of excessive noise are sporting events and a noisy workplace Figure 18.7 The Intensity of Selected Sounds Noise Pollution2 Here are ways to reduce exposure to excessive noise Wear hearing protection around noisy machinery Do not listen to music especially while using earbuds too loud Do not push earbuds in too far Keep the volume lower than you think Do not stand next to speakers at a concert or club Consider wearing ear plugs at such events Avoid exposure to painfully loud sounds Children should use “over the ear” headphones with a sound filter or limiter You and the Environment Making simple changes in your life can combat the confusing array of complex environmental issues Share what you learn about environmental issues with friends and family Join or support organizations working on environmental issues that are important to you Contact your elected representatives and communicate your concerns Summary1 Environmental health encompasses all the interactions of humans with their environment and the health consequences of those interactions. The world’s population is increasing rapidly, especially in the developing world. Factors that may eventually limit human population are food, availability of land and water, energy, and minimum acceptable standard of living. Increased amounts of air pollutants are dangerous for children, older adults and those with respiratory problems Factors include smog, hot weather, heavy motor vehicle traffic and stagnant air Carbon dioxide and other natural gases contribute to the greenhouse effect Summary2 Concerns with water quality focus on pathogenic organisms and hazardous chemicals from industry and households, as well as on water shortages. Sewage treatment prevents pathogens from contaminating drinking water; it often must also deal with heavy metals and hazardous chemicals. The amount of garbage is growing all the time; organic waste from kitchens and yards is the biggest component. Reusing, reducing, and recycling can help reduce solid waste-disposal problems. Potentially hazardous chemical pollutants include asbestos, lead, pesticides, mercury, and many household products. Proper handling and disposal are critical. Summary3 Radiation can cause radiation sickness, chromosome damage, and cancer, among other health problems Loud or persistent noise can lead to hearing loss and stress; two common sources of excessive noise are the workplace and music concerts.