Effect of Environmental Pollution on Humans, Ecosystems and Communities

1- Describe how potentially toxic chemicals are identified and describe some potential impacts on humans, especially children.

Toxicology is the study of the effects of toxic chemicals on human health. One way to determine toxicity of a chemical is to administer various doses to populations of laboratory animals, measure the response, and use these data to predict the chemical effects on humans. If a dose kills 50% of the population, then that is the lethal dose-50%, or LD50. The ED50, or effective dose-50% is the point when 50% of the population experience whatever response is under study. Humans are frequently exposed to various combinations of chemical compounds, like cigarette smoke and exhaust. Children are more susceptible to most chemicals than are adults because their bodies are still developing and are not as effective in dealing with toxicants. Because they weigh less than adults, the same dosage of a chemical can be a lot more potent. Research supports an emerging hypothesis that exposure to pesticides may affect the development of intelligence and motor skills of infants, toddlers, and preschoolers. Chemicals like pesticides can have long term effects on babies when pregnant women are exposed to them. They can delay mental development and cause pervasive development disorder.

2- What environmental catastrophe was largely responsible for replacement of the dilution paradigm by the boomerang paradigm?

The dilution paradigm believes that "the solution to pollution is dilution," meaning that pollution discarded into the environment would be diluted sufficiently to cause no harm. This was the widely-hold belief before Love Canal in the 1940's. A chemical company dumped toxic waste into a pit near the community, causing people to have to abandon their homes, and causing birth defects, including enlarged body parts. The waste was buried 20-25 ft below the surface, and then covered with soil, where vegetation began to grow. The dump site was only in operation until 1953, but the effects of the toxicants were still prevalent well into the 70's, meaning the pollution was not diluted. Today, the dilution paradigm is widely replaced by the boomerang paradigm: "what you throw away can come back and hurt you."

3- Share your thoughts on the relationships between environmental pollution, human health, environmental health. You have total control of this part of the post.
Clearly, things like disposal of toxic chemicals have negative effects on human health, as demonstrated by the Love Canal incident, and the health of the environment is directly linked to the amount of environmental pollution. The relationship between environmental pollution, human health, and environmental health is a direct line of cause to effect. When, say, a river is polluted, the environmental health of that river declines, and people living around it, or using the river experience side effects from the pollution, impacting their health.