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 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 or 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

properties that make a system more than the sum of its parts

ecological diseases

sudden, wide-spread epidemics among livestock and wild species

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

toxins toxic

poisonous chemicals that react with specific cellular components to kill cells or to alter growth or development in undesirable ways; often harmful, even in dilute concentrations

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 within 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 tragic 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

synergism

when an injury caused by exposure to two environmental factors together is greater than the sum of exposure to each factor individually

LD50

a chemical dose lethal to 50 percent of a test population

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