NaimExplain

Describe the aim of the Stockholm Convention. Answer:A treaty, to address toxic chemicals that persist in the environment, bioaccumulate in the food chain, and have the ability to travel long distances

Compare and contrast the safety approach of the U.S. as opposed to the European nations. Answer:Europe: products are tested extensively in an effort to bring only safe substances to market. This approach helps to minimize potentially harmful products from being brought to market, but it takes time and it may delay some perfectly safe products from being utilized. US: "innocent until proven guilty" approach, allows products to be introduced to the market with limited testing and then recalls substances if potentially harmful substances are found to be unsafe after additional testing is conducted.

Distinguish between risk assessment and risk management. Answer:Risk assessment is a process by which risk is quantified and compared in an effort to identify potential problems. Risk assessment, when applied to the field of environmental health helps to determine if a substance or activity might pose a health threat to people or wildlife.

Define the term "risk" as applied to hazard exposure. Answer:Defined as the mathematical probability that an action or substance will result in harm.

Explain the concept of "synergistic effects" when considering mixes of chemicals. Answer:Chemical substances introduced simultaneously can sometimes cancel out each other's effects, sum each other's affects, or multiply each other's effects

Distinguish between "acute exposure" and "chronic exposure." Answer: Acute exposure : exposure is a high exposure over a short period. Chronic exposure : low exposure over a long period.

Distinguish between an "LD50," an ED50," and a threshold dose. Answer: LD50 : scientists calculate the amount of toxicant it took to kill half of the animals tested. ED50 : defined as the amount of a chemical it takes for 50% of the test population to be affected in an adverse way.

Explain the reasoning behind a "dose-response curve." Answer:Measure the effect of the toxicant at different doses or alternatively, the number of animals affected by different doses of the toxicant. The data is plotted on a graph.

Methods of studying hazards: Animal testing Answer:Epidemiological studies are time-intensive and the resultant affects could be attributed to factors other than the toxicant of interest, it is often necessary to conduct laboratory experiments to establish causation

Methods of studying hazards: Epidemiological studies Answer:Compares information among groups of people (usually an exposed and a non-exposed group). The potential effects are tracked generally for an extended period and specific effects are measured and calculated (e.g., death or cancer rates). Statistics are then employed to determine if there is a significant difference between the two groups, which may indicate that a toxicant was responsible. Unethical to use on humans so animal testing.

Methods of studying hazards: case history approach Answer:If the subjects of interest are humans, however, scientists rely on case histories, epidemiological studies, and animal testing. Initially, scientists will study sick individuals by taking down information in case histories, but they are limited in providing information on long-term effects and the probability/risk of a toxicant.

Describe how toxicants move through food chains by biomagnifications. Answer:Toxicants that are fat or oil soluble can be retained in the fat or muscle tissues of animals, causing them to build up (called bioaccumulation). When an animal consumes another animal that contains toxicants in their tissues, the toxicants continue to build up and the resultant concentration can magnify in a process called biomagnification.

Summarize the findings in Rachel Carson's book Silent Spring. Answer:The book documented detrimental effects of pesticides on the environment, particularly on birds. Carson accused the chemical industry of spreading disinformation, and public officials of accepting industry claims uncritically. The book argued that uncontrolled and unexamined pesticide use was harming and even killing not only animals and birds, but also humans

Explain the biological significance of "endocrine disruptors." Answer:Endocrine disruptors because these toxicants may be quite widespread. Chemicals in this category can interfere with the normal functioning of hormones in animals by either blocking the action of naturally-occurring hormones, breaking down the naturally-occurring hormones, or by mimicking naturally-occurring hormones. When a compound mimics a naturally-occurring hormone, such as estrogen, it can result in feminization of male animals, as seen in the Florida alligators. This is an important section to read and understand so careful notes should be taken.

Define the term "infectious disease." Answer:Infectious diseases (also called communicable or transmissible diseases) occur when a pathogen attacks a host, resulting in illness.

Name and describe two specific environmental hazards that are: Cultural Answer:Cultural hazards are lifestyle hazards like smoking, which affect people's health.

Name and describe two specific environmental hazards that are: Biological Answer:Biological hazards results from interactions between organisms, resulting in an infectious disease.

Name and describe two specific environmental hazards that are: Chemical Answer:Chemical hazards are man-made toxicants like those created as pesticides and disinfectants. As mentioned in the Central Case, some of these chemicals mimic hormones that can interfere with normal endocrine systems, which in turn, negatively affect the reproductive health of animals.

Name and describe two specific environmental hazards that are: Physical Answer:Physical hazards are naturally occurring, including examples such as earthquakes, ultraviolet radiation, fires, floods, and blizzards.

Summarize Gillette's findings studying alligators in Florida. Answer:Reproductive abnormalities in Florida alligators that are believed to be linked with endocrine disruptors. Endocrine disruptors are chemicals that interfere with the endocrine (hormone) system, which in part, controls reproductive hormones. This research on the Florida alligators falls under a broad field of environmental health, which aims to assess environmental factors that would influence and affect human health and quality of life. Included in environmental health are impacts of human-made chemicals on the health of not only humans, but also wildlife like the Florida alligator.