Effects of Environmental Toxins

Smog Effects on Human Health

Photo of smog over the city of Beijing On a smoggy day, you're breathing garbage. No different from tossing trash out of a car window with no intention of picking it up, we spew trash into the air as we drive, as we heat our homes, and as we manufacture goods. Would we tolerate all this trash if it were in our houses laying on the ground?

Human health suffers in locations with high levels of air pollution.

Pollutants and their Effects

Different pollutants have different health effects:

Lead is the most common toxic material and is responsible for lead poisoning.
Carbon monoxide can kill people in poorly ventilated spaces, such as tunnels.
Nitrogen and sulfur-oxides cause lung disease and increased rates of asthma, emphysema, and viral infections such as the flu.
Ozone damages the human respiratory system, causing lung disease. High ozone levels are also associated with increased heart disease and cancer.
Particulates enter the lungs and cause heart or lung disease. When particulate levels are high, asthma attacks are more common. By some estimates, 30,000 deaths a year in the United States are caused by fine particle pollution.

Human Illnesses from Air Pollution

Picture of a lung x-ray Many but not all cases of asthma can be linked to air pollution. During the 1996 Olympic Games, Atlanta, Georgia, closed off their downtown to private vehicles. This action decreased ozone levels by 28%. At the same time, there were 40% fewer hospital visits for asthma. Can scientists conclude without a shadow of a doubt that the reduction in ozone caused the reduction in hospital visits? What could they do to make that determination?

Among patients who are diagnosed with lung cancer, 15% of them have never smoked. This rate is currently increasing. One study showed that the risk of being afflicted with lung cancer increases directly with a person's exposure to air pollution. The study concluded that no level of air pollution should be considered safe. Exposure to smog also increased the risk of dying from any cause, including heart disease.

One study found that in the United States, children develop asthma at more than twice the rate of two decades ago and at four times the rate of children in Canada. Adults also suffer from air pollution-related illnesses that include lung disease, heart disease, lung cancer, and weakened immune systems. The asthma rate worldwide is rising from 20% to 50% every decade.

CK-12.org text and images logo COPD or chronic obstructive pulmonary disease is a consequence of smoking and or routine or chronic exposure to respiratory toxins. This category of noninfectious disease, which includes emphysema and chronic bronchitis, is caused by permanent changes to the tissue. See the image below.

Graphic of a person's lungs with COPD

Be sure to watch this video, Acknowledging the Link Between Air Pollution and Health.

Pollutants - Our Toxic Environment

Environmental toxins can have many acute (short term- that can include death) and or chronic (long term) consequences on human health as shown in the image below.

Health effects of pollution graphic

General Effects of Pollutants

Almost every part of the human body can be affected by some pollutant, infectious agent, or toxic chemical. For example, lead and mercury affect the nervous system; arsenic, the skin; carbon monoxide, the cardiovascular system; beryllium, the kidneys, and fluoride, the bones.

A dose-response curve graph Dose-response is a measure of when a chemical has an appreciable effect on an organism. An example of a dose-response curve is shown in the image below. It is generally observed that the greater the dose, the greater the response to a chemical (up to a certain point). This is how much exposure to medicine, pesticide, or other toxin is considered safe or effective.

The effects of every chemical (including routine medicines) differ greatly among and between species. For example, the kinds of vegetation that can live nearest to a toxic source are often small plants with relatively short lifetimes as their adaptations are for survival in harsh and highly variable environments. Farther from the toxic source, trees may be able to survive. Changes in vegetation and other organisms with distance from a toxic substance define the ecological gradient for the toxin and the environment.

NIMBY

NIMBY is an acronym meaning not in my backyard, and it is a characteristic response to perceived potentially negative changes in our environment. NIMBY may be a response to building public housing or a new landfill. Education and affluence are key to whether a community is able to prevent these changes, but often toxins are routinely released into our environment without our realizing. The satellite image below shows a landfill in northern Georgia in the middle of several large subdivisions. It is literally in the backyards of many of these houses.

Satellite image of subdivisions built near a landfill

For more on NIMBY, see these websites which are databases for known, point source pollutants in our environment.

CHE Toxicant and Disease Database

Scorecard (The Pollution Information Site)

EPA's My Environment

RESOURCES IN THIS MODULE ARE OPEN EDUCATIONAL RESOURCES (OER) OR CREATED BY GAVS UNLESS OTHERWISE NOTED. SOME IMAGES USED UNDER SUBSCRIPTION.