Environmental Issues:

Making a DifferenceChapter 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

Water and water quality

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 sources

Water supplies contaminated by industrial and agricultural wastes

Found in the wrong place at the wrong time causing conflicts between regions

Problems

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.

How these problems are solved

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.

Water pollution

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

and parking lots

Sources of surface water pollution

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

Sources of ground water pollution

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

Types of water pollutants

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.

Safe drinking water solutions

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?

Activity

Atmosphere

Air and air quality

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

Air pollution

EPA Air Quality Index (AQI)

AIRNow - Homepage

Highly reactive gas Poisonous to most living organisms Causes respiratory irritation, aggravates

respiratory and heart disease and damages the lungs.

Ozone

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.

Particulate matter

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.

Smog

Schanghai 1993

Photochemical smog and temperature inversion

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.

Acid deposit and precipitation

Thinning of the ozone layer of the atmosphere

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?

Global warming

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).

Predicted effects of global warming

Kyoto protocol (1997)◦ Called for the nations to cut their emmisions of greenhouse gases, particularly

CO2, by about 5,2% below 1990 levels by 2012.◦ 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

What has been done?

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

Indoor air pollution

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.

Waste management

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.

Hazardous waste

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.

Types of hazardous waste

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

Approaches to waste management

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.

Ecosystems and biodiversity

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.

Effects of human influence on ecosystems

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.

Effects of human influence on ecosystems

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.

Effects of human influence on ecosystems

World population growth

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.

How many people can the planet support?

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 2050.

◦ 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.

Approaches to population control

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.