HCL-PHS 121 Final ch 1-10

Hippocrates contribution to the history of environmental health

father of modern medicine

• linked the influence of environment to disease

John Snow contribution to history of environmental health

• icon in history of public health

• linked cholera outbreak cause to water pumps in London

Upton Sinclair contribution to history of environmental health

• instrumental in passage of the first Food and Drug Act (1906)

• Described conditions in meat processing industry in Chicago

Public Health Act of 1848’s purpose

The British Parliament enacted the Public Health Acts of 1848 to promote clean water and control infectious diseases. There were major outbreaks of cholera, including an outbreak in NYC in 1849 that killed 5,000 people

Contributions of epidemiology to environmental health

• Concern with populations

• Use of observational data

• Methodology for study designs

• Descriptive and analytic studies

Concern with populations

studies the entire population compared to clinical medicine

use of observation data

takes advantage of naturally occurring situations in order to study the occurrence of disease

Methodology for research designs

• Research conducted on environmentally caused disease in the population use the following study designs

  • cross sectional

  • ecological

  • case-control

  • cohort

Descriptive studies

• Descriptive

  • outline of the occurrence of disease in populations according to classification by person, place, and time variables

    • i.e. demographics such as age, race, sex

      • place refers to a specific country

      • time refers to a month, year, etc

Analytic studies

Examines causal hypotheses regarding the association between exposures and health conditions

• i.e. natural experiments - naturally occurring circumstances in which subsets of the population have different levels of exposure to a hypothesized causal factor in a situation resembling an actual experiment

Nuisances removal and disease prevention amendments bill

• january 23, 1855

• a reform of the Victorian public health legislation about the 1854 cholera outbreak

• the intent of the bill was to control release into the atmosphere of fumes from operations such as gas works, silk boiling works, and bone boiling factories

Factors that affect responses to a toxic chemical

• toxicity

• dose

• synergism

• additive effects

• potentiation

• antagonism

• exposures

Toxicity

the degree to which something is poisoning

• related to the chemical and physical poisoning

Dose

the amount of a substance administered at one time

• account for received doses of the chemical

• duration of exposure

  • acute

  • subacute

  • subchronic

  • chronic

• Interactions that transpire among multiple chemicals

• individual sensitivity

Synergism

combined effect of exposures to 2 or more chemicals greater than the sum of their individual effect

Additive effects

combination of 2 chemicals produces an effect that is = to their individual effects added together

Potentiation

a chemical causes another chemical to become toxic

antagonism

2 chemicals given together interfere with each other’s actions or one interferes with the action of the other

exposures

• ingestion

• injections into the bloodstream

• contact with the surface of the skin

• inhalation

Surface water

• all water on the surface

  • i.e. rivers, lakes, streams, and surface springs

groundwater

• water contained in the interconnected pores in an aquifer

• any water that is stored naturally deep underground in aquifers or that flows through rock or soil, supplying springs and wells; this water is less susceptible to contamination than surface water

finished water

water leaving a treatment plant and ready to be used by consumers after being collected, treated, and usually filtered

source water

the untreated and unfiltered water in rivers, streams, lakes, and aquifers from which water utilities draw water to be treated, filtered, and tested to produce drinking water

Concept of bioaccumulation as it relates to specific metals

• also known as biomagnification

• substances become more toxic as they move up the food chain

• given options in regards to specific metals???

acid rain components

sulfur dioxide and nitrogen oxides emitted into the atmosphere and transported by wind and air currents

Criteria air pollutants as listed by the EPA

used to describe a group of very common air pollutants regulated by the EPA on the basis of criteria (information on health and/or the environmental effects of pollution)

• ozone

• nitrogen oxide

• carbon monoxide

• aerosol particles

• sulfur dioxide

• volatile organic compounds

• pick the one that belongs

Ozone

variety of O2 formed by chemical reactions of pollutants

Nitrogen oxide

combustion of fuels, cars, trucks, react with volatile organic compounds = smog

carbon monoxide

colorless, odorless, poisonous gas produced by incomplete burning of solid, liquid, gaseous fluids

aerosol particles

diesel exhaust, smoke from incineration (dust, soot)

sulfur dioxide

burning of fossil fuels; industrial processes i.e. production of paper

volatile organic compounds

chemicals that contain carbon; product of fuel combustion

concept of temperature inversion

atmospheric condition during which a warm layer of air stalls above a layer of cool air that is closer to the surface of the earth.

• pollutants can get stuck as they are trapped closer to the earth’s surface

vulnerable groups

• elderly

• children

• people with chronic diseases

waterborne pathogens

• enteric protozoal parasites

• bacterial enteropathogens

• viral pathogens

• other agents

enteric protozoal pathogens

• entamoeba histolytica

• giardia intestinalis

• cryptosporidium parvum

• cyclospera cayetansis

bacterial enteropathogens

• salmonella

• shigella

• e. coli

• vibrio cholera

• campylobacter 

Viral pathogens

• enteroviruses

• adenoviruses

• noroviruses

other agents (waterborne pathogens)

• legionella pneumophila

• dracunculus medinensis