Environmental Health

Introduction
Air Pollution
Water Pollution
Mercury
How can mercury affect my health?
Asbestos
Lead Poisoning

Environmental Health is the field of science that studies how the environment influences human health and disease.

"Environment,” in this context, means things in the natural environment like air, water and soil, and also all the physical, chemical, biological and social features of our surroundings.

The man-made, or “built,” environment includes physical structures where people live and work such as homes, offices, schools, farms and factories, as well as community systems such as roads and transportation systems, land use practices and waste management. Consequences of human alteration to the natural environment, such as air pollution, are also parts of the man-made environment.

Our environment affects our health. Our average life span has almost doubled over the past century or so mainly because we have clean, safe drinking water. If parts of the environment, like air and water, or soil become polluted, it can lead to health problems. For example, asthma attacks can result from pollutants and other chemicals in the air and in the home.

Some environmental risks are a part of the natural world, like radon in the soil. Others are the result of human activities, like lead poisoning from paint, or exposure to asbestos or mercury from mining or industrial use.

The social environment encompasses lifestyle factors like diet and exercise, socioeconomic status, and other societal influences that may affect health.

Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's also called smog.

Some air pollutants are poisonous. Inhaling them can increase the chance you'll have health problems. People with heart or lung disease, older adults and children are at greater risk from air pollution. Air pollution isn't just outside – the air inside buildings can also be polluted and affect your health.

What is ozone?

Ozone is a gas that occurs both in the Earth's upper atmosphere and at ground level. Ozone can be good or bad, depending on where it is found:

Good Ozone. Ozone occurs naturally in the Earth's upper atmosphere-10 to 30 miles above the Earth's surface-where it shields us from the sun's harmful ultraviolet rays.

Bad Ozone. In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone pollution is a concern during the summer months when the weather conditions needed to form ground-level ozone-lots of sun, hot temperatures-normally occur.

Indoor Air Pollution

We usually think of air pollution as being outdoors, but the air in your house or office could also be polluted. Sources of indoor pollution include

• Biological contaminants like mold and pollen
• Tobacco smoke
• Household products and pesticides
• Gases such as radon and carbon monoxide
• Materials used in the building such as asbestos, formaldehyde and lead

Sick building syndrome occurs when several people are affected, but no specific source of the illness is found. Indoor air quality problems usually only cause discomfort, and most people feel better as soon as they eliminate the source of the pollution. However, some pollutants can cause diseases that show up much later, such as respiratory diseases or cancer. Making sure that your building is well-ventilated and eliminating pollutants can improve the quality of your indoor air

Molds

Molds are fungi that can be found both outdoors and indoors. They grow best in warm, damp and humid conditions. If you have damp or wet spots in your house, you will probably get mold. Mold can cause health problems. Inhaling or touching mold or mold spores may cause allergic reactions or asthma attacks in sensitive people. It can cause fungal infections. In addition, mold exposure may irritate your eyes, skin, nose, throat and lungs.

Pesticide

A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests. Under United States law, a pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.

Radon

Radon is a cancer-causing, radioactive gas. You can't see radon. And you can't smell it or taste it. But it may be a problem in your home. Radon is estimated to cause many thousands of deaths each year. That's because when you breathe air containing radon, you can get lung cancer. In fact, the Surgeon General has warned that radon is the second leading cause of lung cancer in the United States today. Only smoking causes more lung cancer deaths. If you smoke and your home has high radon levels, your risk of lung cancer is especially high.

Radon comes from the natural (radioactive) breakdown of uranium in soil, rock and water and gets into the air you breathe. Radon can be found all over the U.S. It can get into any type of building - homes, offices, and schools - and result in a high indoor radon level. But you and your family are most likely to get your greatest exposure at home, where you spend most of your time.

Radon is a radioactive gas. It comes from the natural decay of uranium that is found in nearly all soils. It typically moves up through the ground to the air above and into your home through cracks and other holes in the foundation. Your home traps radon inside, where it can build up. Any home may have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements.

Carbonmonoxide

Carbon monoxide, or CO, is an odorless, colorless gas that can cause sudden illness and death. CO is found in combustion fumes, such as those produced by cars and trucks, small gasoline engines, stoves, lanterns, burning charcoal and wood, and gas ranges and heating systems. CO from these sources can build up in enclosed or semi-enclosed spaces. People and animals in these spaces can be poisoned by breathing it.

The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. High levels of CO ingestion can cause loss of consciousness and death. Unless suspected, CO poisoning can be difficult to diagnose because the symptoms mimic other illnesses. People who are sleeping or intoxicated can die from CO poisoning before ever experiencing symptoms.

All people and animals are at risk for CO poisoning. Certain groups — unborn babies, infants, and people with chronic heart disease, anemia, or respiratory problems — are more susceptible to its effects. Each year, more than 500 Americans die from unintentional CO poisoning, and more than 2,000 commit suicide by intentionally poisoning themselves.

We all need clean water. People need it to grow crops and to operate factories, and for drinking and recreation. Fish and wildlife depend on it to survive.

Many different pollutants can harm our rivers, streams, lakes and oceans. The three most common are soil, nutrients and bacteria. Rain washes soil into streams and rivers. The soil can kill tiny animals and fish eggs. It can clog the gills of fish and block light so plants die. Nutrients, often from fertilizers, cause problems in lakes, ponds and reservoirs. Nitrogen and phosphorus make algae grow and can turn water green. Bacteria, often from sewage spills, can pollute fresh or salt water.

Every living creature needs clean and safe drinking water. How much do you need? It depends - your size, activity level and the weather all make a difference.

The water you drink is a combination of surface water and groundwater. Surface water includes rivers, lakes and reservoirs. Groundwater comes from underground. The United States has one of the safest water supplies in the world, but drinking water quality can vary from place to place. It depends on the condition of the source water and the treatment it receives. Treatment may include adding fluoride to prevent cavities and chlorine to kill germs.

Your water supplier must give you annual reports on drinking water. The reports include where your water came from and what contaminants are in it.

Mercury is a naturally occurring metal which has several forms. The metallic mercury is a shiny, silver-white, odorless liquid. If heated, it is a colorless, odorless gas.

Mercury combines with other elements, such as chlorine, sulfur, or oxygen, to form inorganic mercury compounds or "salts," which are usually white powders or crystals. Mercury also combines with carbon to make organic mercury compounds. The most common one, methylmercury, is produced mainly by microscopic organisms in the water and soil. More mercury in the environment can increase the amounts of methylmercury that these small organisms make.

Metallic mercury is used to produce chlorine gas and caustic soda, and is also used in thermometers, dental fillings, and batteries. Mercury salts are sometimes used in skin lightening creams and as antiseptic creams and ointments.

The nervous system is very sensitive to all forms of mercury. Methylmercury and metallic mercury vapors are more harmful than other forms, because more mercury in these forms reaches the brain. Exposure to high levels of metallic, inorganic, or organic mercury can permanently damage the brain, kidneys, and developing fetus. Effects on brain functioning may result in irritability, shyness, tremors, changes in vision or hearing, and memory problems.

Short-term exposure to high levels of metallic mercury vapors may cause effects including lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation.

"Asbestos" is the name of a group of similar minerals with separable, long, and thin fibers. Asbestos fibers are so small they cannot be seen. These tiny fibers are only dangerous if they are disturbed, causing fibers to float in the air and allowing them to be easily inhaled. Asbestos has long been recognized as a health threat to humans, because the fibers can be inhaled and are difficult to remove from the lungs.

The combined use of detection methods called light microscopy, electron microscopy, and energy dispersive X-ray analysis offer the most accurate approach to identify asbestos and to estimate concentrations that may become airborne upon disturbance. For the purposes of counting asbestos fibers in these samples, regulatory agencies commonly count as fibers those particles of asbestos minerals at least 5 micrometers in length and with length:width ratios of 3:1. For other purposes, such as detecting fibers in bulk building materials, asbestos particles with length:width ratios of 5:1 are counted. Air concentrations of asbestos fibers in ambient (typical) air are 0.00001 to 0.0001 fibers per milliliter (fiber/mL). The recently established exposure limit for U.S. workplaces is 0.1 fiber/mL.

Lead is a metal that occurs naturally in the earth's crust. People have spread it through the environment in many ways. Lead used to be in paint and gasoline. Lead can still be found in contaminated soil, household dust, drinking water, lead-glazed pottery and some metal jewelry.

Breathing air, drinking water, eating food or swallowing or touching dirt that contains lead can cause many health problems. In adults, lead can increase blood pressure and cause infertility, nerve disorders and muscle and joint pain. It can also make you irritable and affect your ability to concentrate and remember.

Lead is especially dangerous for children. A child who swallows large amounts of lead may develop anemia, severe stomachache, muscle weakness and brain damage. Even low levels of lead are linked to lower IQ scores.