Chapter 8: Environmental Health and Toxicology

health

A state of physical and emotional well-being; the absence of disease or ailment.

disease

A deleterious change in the body's condition in response to destabilizing factors, such as nutrition, chemicals, or biological agents.

morbidity

Illness or disease.

mortality

Death rate in a population, such as number of deaths per thousand people per year.

environmental health

The science of external factors that cause disease, including elements of the natural, social, cultural, and technological worlds in which we live.

disability-adjusted life years (DALYs)

A health measure that assesses the total burden of disease by combining premature deaths and loss of a healthy life that result from illness of disability.

pathogens

Organisms that produce disease in host organisms, disease being an alteration of one or more metabolic functions in response to the presence of the organisms.

emergent diseases

A new disease or one that has been absent for a least 20 years.

conservation medicine

Attempts to understand how changes we make in our environment threaten our health as well as that of natural communities on which we depend.

toxic

A substance that is poisonous.

toxicology

The study of the adverse effects of external factors on an organism or a system.

toxicants

Nonbiological noxious substances.

environmental toxicology (ecotoxicology)

The study the interactions, transformation, fate, and effects of toxic materials in the biosphere, including individual organisms, populations, and whole ecosystems.

allergens

Substances that activate the immune system and cause an allergic response; may not be directly antigenic themselves but may make other materials antigenic.

antigens

Substances that stimulate the production of, and react with, specific antibodies.

sick building syndrome

A cluster of allergies and other illnesses caused by sensitivity to molds, synthetic chemicals, or other harmful compounds trapped in insufficiently ventilated buildings.

neurotoxins

Toxic substances, such as lead or mercury, that specifically poison nerve cells.

mutagens

Agents, such as chemicals or radiation, that damage or alter genetic material (DNA) in cells.

teratogens

Chemicals or other factors that specifically cause abnormalities during embryonic growth and development.

fetal alcohol syndrome

A set of permanent physical, mental, and behavioral birth defects that result when mothers drink alcohol during pregnancy.

carcinogens

Substances that cause cancer

cancer

Invasive, out-of-control cell growth that results in malignant tumors.

endocrine hormone disrupters

Chemicals that interfere with the function of endocrine hormones such as estrogen, testosterone, thyroxine, adrenaline, or cortisone.

bioaccumulation

The selective absorption and concentration of molecules by cells.

biomagnification

Increase in concentration of certain stable chemicals (for example, heavy metals or fat-soluble pesticides) in successively higher trophic levels of a food chain or web.

persistent organic pollutants (POPs)

Chemical compounds that persist in the environment and retain biological activity for a long time.

LD50

A chemical dose lethal to 50 percent of a test population.

retrospective study

A study that looks back in history at a group of people (or other organisms) who suffer from some condition to try to identify something in their past life that the whole group shares but that is not found in the histories of a control group as near as possible to those being studied but who do not suffer from the same condition.

prospective study

A study in which experimental and control groups are identified before exposure to some factor. The groups are then monitored and compared for a specific time after the exposure to determine any effects the factor may have.

acute effects

A sudden onset of symptoms or effects of exposure to some factor.

chronic effects

Long-lasting results of exposure to a toxin; can be a permanent change caused by a single, acute exposure or a continuous, low-level exposure.

hormesis

Nonlinear effects of toxic materials.

epigenome

DNA and its associated proteins and other small molecules that regulate gene function in ways that can affect multiple generations.

risk

The probability that something undesirable will happen as a consequence of exposure to a hazard.

risk management

Combines principles of environmental health and toxicology with regulatory decisions based on socioeconomic, technical, and political considerations.

risk assessment

Evaluation of the short-term and long-term risks associated with a particular activity or hazard; usually compared with benefits in a cost-benefit analysis.