Environmental Engineering Reference
In-Depth Information
Convention on Long-Range Transboundary Air Pollution
United Nations Convention on the Law of the Sea
Convention on the Prior Informed Consent (PIC) Procedure for Certain Hazardous Chemicals and Pesti-
cides in International Trade
International Convention on Oil Pollution Preparedness, Response, and Cooperation
International Atomic Energy Agency Convention on Nuclear Safety
Protection of the Arctic Marine Environment (PAME)
Impacts on the Environment and Human Health
Pollution can break down quickly in the environment and cause relatively little harm, or it can persist for years,
decades, centuries, or millennia depending on the pollution type and quantity. Detrimental affects of pollution
can impact human, wildlife, and ecosystem health.
Hazards to Human Health
Exposure
Exposure to health hazards can be long-term or short-term, in high or low doses.
Acute exposure
occurs when
someone is exposed to a high dose for a brief period of time, whereas
chronic exposure
occurs repeatedly over
a long period of time but in small doses. Historic examples of chronic exposure include the many people who
had frequent contact with lead, asbestos, or mercury, all of which were considered harmless at the time. In fact,
low-dose, one-time exposure to these substances is unlikely to be harmful. However, chronic exposure to lead,
mercury, or asbestos can lead to life-threatening conditions. There are many examples of acute exposure, in-
cluding a one-time experience of high radiation or inhalation of toxic gas. Generally, it is easier to identify the
source of acute exposure, since it is usually related to an event, as opposed to exposure over an extended peri-
od of time.
Environmental Risk Analysis
A
risk analysis
assesses the environmental risks potentially associated with an event or action. Any environ-
mental risk is balanced against the associated monetary value, and recommendations are included for mitigat-
ing risk. A risk analysis also helps concerned parties better understand the toxins and pollutants involved in the
event and their effects on humans and ecosystems, the potential for human exposure to the threat, and people's
perceptions of the risk. A
dose-response analysis
can be used to determine the toxicity and threat to human
and wildlife health, and a
cost-benefit analysis
provides the final overview of the proposed action.
Despite research and testing, the effects of substances are not fully known until they are used; therefore, some
countries and companies use the
precautionary principle
when evaluating a substance's toxicity. This means
assuming the product is harmful until proven otherwise. In contrast to this is the
innocent-until-proven-guilty
approach, in which a product is assumed to be harmless until proven otherwise. Obviously, the latter approach
is somewhat riskier (and usually less expensive) and can potentially lead to health problems or death. The Un-
ited States often uses the innocent-until-proven-guilty approach, while Europe commonly uses the precaution-
ary principle.
