Chapter 12

 When we look at environmental issues, we become aware that our lives are part of the intricate web of living organisms and nonliving natural resources that make the planet a single, vital ecosystem.  Environmental health has traditionally been concerned with infectious diseases associated with contaminated water, air, food, waste and other pollutants.

 Water cycle

 Surface water ◦ Precipitation that is stored in lakes, reservoirs and wetlands  Groundwater ◦ Precipitation that sinks into the ground ◦ Stored in giant underground reservoirs called aquifers ◦ Represent 95% of the world’s supply of freshwater

 Water supplies contaminated by industrial and agricultural wastes  Found in the wrong place at the wrong time causing conflicts between regions

 Building dams and reservoirs to store surface water  Transfer surface water from one area to another via pipelines and canals  Withdrawing ground water  Converting salt water to freshwater  Adopting water conservation methods ◦ Xeriscaping: replacement of green lawns in arid and semi-arid regions ◦ Drip irrigation systems ◦ Ordinances requiring water conservation ◦ Low-flow toilets ◦ Water cost raising to reduce use ◦ Building codes for the use of water-efficient fixtures or appliances. ◦ Individual contribution to water conservation.

 Defined as any chemical, biological or physical change in water quality that has harmful impact on living organisms or makes water unsuitable for desired use.

 Factories  Sewage treatment plants  Active and abandoned mines  Oil spills  Agricultural feedlots  Runoff from croplands, golf courses, lawns and parking lots

 Storage lagoons  Septic tanks  Landfills  Hazardous waste dumps  Underground storage tanks filled with gasoline, oil, solvents, and hazardous waste  Dumping or spilling of oil, gasoline, paint thinners or other organic solvents onto the ground

 Biological ◦ Bacteria, viruses and parasites ◦ Short lived ◦ Mainly cause gastrointestinal problems  Chemical ◦ Inorganic chemicals (acids, toxic metals, salts) ◦ Organic chemicals (cleaning solvents, petroleum products, plastics, pesticides, detergents) ◦ Sediment (salt, silt) ◦ Radioactive materials ( radon, uranium, isotopes, iodine) ◦ Long lasting health problems, including cancer, liver and kidney damage, and birth defects

 Safe drinking water act (SDWA, 1974) ◦ Established many health standards for drinking water.  Home water treatment devices  Bottled water  It is of special concern the contamination in older homes from lead water pipes and lead solder on pipes.

 Ensuring a sustainable water supply for ourselves and future generations will require several strategies: ◦ Consumers and businesses need to use water saving technologies ◦ Farmers and the agriculture industry need to develop ways to irrigate crops more efficiently ◦ Government and policy makers must manage water basins and groundwater fairly and effectively.  Failure to address our water- related problems will lead to economic and health problems, increased environmental degradation and loss of biodiversity.

 Who best conserves fresh water? Read “Beating the Odds” pg 349  How can you help to conserve water?

 Atmosphere Greenhouse gases Ozone

 The presence of one or more chemicals in the atmosphere in sufficient quality and quantity to cause harm to life.  EPA  Criteria pollutants ◦ Carbon monoxide ◦ Sulfur dioxide ◦ Nitrogen dioxide ◦ Suspended particulate matter ◦ Ground level ozone ◦ Metal and metal compounds

 EPA  Air Quality Index (AQI)

 Highly reactive gas  Poisonous to most living organisms  Causes respiratory irritation, aggravates respiratory and heart disease and damages the lungs.

 Particles or droplets of dust, soot, oil, metals or other compounds suspended in the air  If found in the lungs for long time cause irritation and damage to alveoli.  Trigger the immune system response, contributing to heart disease and lung disease.

 Mixture of pollutants in the lower atmosphere that makes the air hazy  Two types ◦ Industrial smog  caused primarily by the burning of large amounts of coal and oil for heating, manufacturing and the production of electric power ◦ Photochemical smog  forms when pollutants from motor vehicle exhaust, industry and other sources combine in the presence of sunlight and heat, producing large amounts of ozone and more than 100 other chemicals.

Schanghai 1993

 The degree of environmental damage from acid deposition depends on the ability of the soil to neutralize acid. ◦ Alkaline soils  lower damage ◦ Acid soils  extensive damage.

 For the past few hundred years human activities have increased the amount of greenhouse gases in the lower atmosphere  The intensification of the greenhouse effect has led to global warming.  How is it produced?

 Melting of ice caps and glaciers  Flooding in coastal cities as seas rise  Changed rates of precipitation and evaporation  Storms more frequent and intense  Parts of the world will become drier  Pest and diseases will flourish  Air quality decline (pollution is worse in warm weather).

 Kyoto protocol (1997) ◦ Called for the nations to cut their emmisions of greenhouse gases, particularly CO2, by about 5,2% below 1990 levels by ◦ Allows countries and private companies to trade and sell their greenhouse gas emission allowances to other countries and businesses ◦ Encourages private companies to develop new technologies that reduce greenhouse gas emissions.  US emission reduction plan for the nation (2002) ◦ Calls for voluntary participation by all sectors of the economy.  Promotion of hybrid gas-electric cars and cars with high fuel economy and low emissions.  Increase of fuel economy standards for new cars and light trucks  Public transportation improvements

 Substantial reduction in CO2 emissions will include massive changes in ◦ Industrial processes ◦ Transportation ◦ Energy sources ◦ Personal lifestyles How can you help improve outdoor air quality? ◦ Tune up your car ◦ Walk when you can ◦ Consider buying hybrid cars ◦ Turn down your home’s thermostat and water heater ◦ Buy energy efficient appliances ◦ Keep house plants to help clean the air in your home and plant shade trees outside.

 Indoor air pollution can be higher and more hazardous than air pollution outside  Most common air pollutants are usually higher inside the home than outside

 Solid waste  any unwanted or discarded material that is not liquid or gas.  99% produced by mining, oil and natural gas production, agriculture and industrial activities.  Methods for managing solid waste include burning, burying (landfills) and shipping wastes to other states or countries.

 Any discarded solid or liquid material that meets one or more of four criteria ◦ The material contains a toxic, carcinogenic or mutagenic compound at levels that exceed EPA safety standards (solvents, pesticides) ◦ Catches fire easily (gasoline, oil-based paints) ◦ Reactive or unstable enough to explode or release toxic fumes ( chlorine, chlorine bleach) ◦ Corrodes metal containers (drain cleaners, industrial cleaners)  Top 5 chemical compounds of concern ◦ Arsenic, lead, mercury, vinyl chloride, polychlorinated biphenyls (PCBs)  Exposure occurs when wastes leak from sanitary landfills and contaminate water supplies  Effects of these chemicals include ◦ Cancer, respiratory diseases, neurological damage, developmental deficits.

 Household hazardous waste ◦ Batteries, paints, cleaners, oils and pesticides  Medical waste ◦ Any solid or liquid waste that is generated in the medical diagnosis, treatment or immunization of human beings or animals ◦ Needles and syringes, used culture dishes and other glassware, discarded surgical gloves, blood and blood products, tissue samples and any materials contaminated by contact with such products.  Radiation and radioactive waste ◦ Low level radiation products  x-rays, nuclear medicine diagnosis and radiation therapy  Televisions, computer monitors, microwave ovens, and cell phones. ◦ High level radioactive waste  Nuclear weapons and nuclear power plants.

 Landfills, incinerators and hazardous waste repositories are undesirable in a community.  An alternative is to recycle, reduce and reuse resources  Actions to control and prevent waste include: ◦ Buying recyclable, reusable or compostable products ◦ Composting yard trimmings ◦ Using rechargeable batteries ◦ Using reusable cloth bags for grocery shopping ◦ Reducing use of paper towels and other paper products ◦ Buying products with as little Styrofoam, cardboard or paper packaging as possible ◦ Stopping junk mail

 Ecosystem  an interconnected community of organisms living together in a physical environment as a balanced, mutually supportive system.  Biodiversity  variety of different animal and plant species on Earth.

 An ecologically and biologically diverse planet offers innumerable benefits to humans, including: ◦ Medicine, food and fuel ◦ Recreation, retreat and refreshment ◦ Climate maintenance, water cycling, soil production, waste disposal and pest control.  Human activities have significantly disrupted these ecosystems and caused a decline in biodiversity  Every year, hundreds of plants and animal species become extinct and thousands more are at the risk of extinction.

 Deforestation  removal of trees from a forested area without adequate replanting ◦ About 90% of forest loss is occurring in tropical forests. Although tropical forest make up only 6% of the world’s land, they are home to between 50 – 90% of the terrestrial species.

 Desertification  the conversion of once fruitful land into infertile wasteland or desert. ◦ Everyday, an average of 40 square miles of land are turned into deserts by droughts in combination with human activities, such as livestock grazing, poor irrigation techniques and overplanting of crops.

 Loss of freshwater resources ◦ Nearly half of all freshwater species are now threatened with extinction ◦ Many rivers are threatened by industrial, agricultural and city wastes as well as disruption of water flow by dams, channelization and diversion of water for agricultural irrigation. ◦ Acid rain and runoffs pollute lakes and deplete oxygen in the water ◦ Some lakes have shrunk or dried up when humans withdrew more water from them than could be replaced by rainfall. ◦ Introduction of non-native species disrupts the balance of the ecosystem and usually results in the extinction of native species.

 Global carrying capacity  the number of people the Earth can support at subsistence levels ◦ Subsistence living includes enough food, water, land and energy to survive  Cultural carrying capacity  the number of people the Earth can support at an optimum standard of living ◦ Includes the luxuries that are part of live in the developed world, such as plentiful food, indoor plumbing, cars and air conditioning.

 The global carrying capacity of Earth is 50 billion people  The cultural carrying capacity is much less. ◦ If luxuries are minimized, the cultural carrying capacity could be well above the population of 9 billion projected for ◦ If luxuries are maximized, it is probable lower than the current population of 6 billion  There is probably not enough resources, especially energy resources to extend an optimum standard of living to everyone alive on the planet right now.

 If standards of living are to be improved for all the people in the planet population growth has to be slowed by ◦ Family planning ◦ Empowering women and increasing their access to educational and employment opportunities ◦ Reducing poverty and infant mortality ◦ Improving access to health care ◦ Encourage parents to have fewer, healthier children offering incentives and disincentives to promote smaller families.

 Looking at environmental issues helps us recognize some of the features that characterize life: interdependence, diversity, adaptability and limits  Acknowledging and honoring these characteristics can help us live in harmony with the environment.  Even though environmental health involves human activities all over the glove, each of us can take actions today to reduce the size of that footprint.