Health and Toxicology

8/11/2019 Health and Toxicology

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Health Hazards

Infectious Diseases

Respiratory diseases

pneumonia

tuberculosis

influenza

whooping cough


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Health Hazards

Infectious Diseases - are diseases caused by

the spread of bacteria and pathogens. The

pathogen or any other organism enters thebody and multiplies to survive. Infectious

diseases are contagious and highly

comunicable.


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Health Hazards

Major Infectious Diseases in the Philippines

Degree of risk: high

Food or waterborne diseases:bacterial diarrhea,hepatitis A, and typhoid fever

Vectorborne diseases:dengue fever and malaria

Water contact disease:leptospirosis (2013)


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Health Hazards


Pneumonia


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Health Hazards


Tuberculosis


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Health Hazards


influenza


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Health Hazards


whooping cough


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Classes of Toxic Chemicals

Irritants

Respiratory fibrotic agents

Asphyxiants

Allergens

Neurotoxins

Mutagens

Teratogens

Carcinogens


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Irritantsrefers to a condition in the body when itis trying to react to a localized injury of tissues


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Respiratory fibrotic agentssubstances that cause inflammationof the airways after they are inhaled


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AsphyxiantsA condition in which an extremedecrease in the concentration of oxygen in thebody accompanied by an increase in theconcentration of carbon dioxide leads to loss ofconsciousness or death.


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Allergensany substance (antigen), mostoften eaten or inhaled, that is recognizedby the immune system and causes anallergic reaction


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Neurotoxinssubstances that are inducingadverse effects in the central nervous system,peripheral nerves or sensory organs


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Mutagens substances that causechanges (mutations) in the geneticmaterial of cells


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Teratogenssubstance capable ofinterfering with the development of

a fetus, causing birth defects.


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Carcinogenssubstances or agentsthat cause cancer


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Movements of Toxins in the Environment

Solubility

1. Water soluble compounds move rapidlythrough the environment and have access

to cells.

2. Fat soluble compounds needs a carrierto move through the environment, butonce inside the body they penetrate thetissues easily . They are stored in bodyfats and persist for many years


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Bioaccumulation

The gradual buildup, over time, of a chemicalin a LIVING ORGANISIM


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Why Does This Happen?

Chemicals are taken up faster than they are

used

Or

Chemicals cant be broken down by the

organism for use


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Pollutants

Chemical pollutants that are bioaccumulated

come from many sources

Pesticides

Industrial Smoke Stacks

Automobile Emissions

Deliberate Discharge of Compounds into Water


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Pesticides Industrial Smoke Stacks

Automobile Emissions Deliberate Discharge ofCompounds into Water


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Biomagnification

The buildup of substances by successive trophic levels

Example: A predator will have higher concentrations of a

chemical compared to its prey

DDT

Soil(10ppm)Earthworms(141ppm)Robins(444ppm)


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1 unit

2 units

6 units

12 units

24 units


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DDT

Dicholoro-diphenyl-trichloroethane

An insecticide used in the 40s, 50s and 60s

entered the environment in run-off from land

Was banned in 1972 after the Bald Eagle

population had a noticeable crash.


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DDT


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Persistencethe amount of time a

pesticide remains in the environment,

measured by half-life. Pesticides with

longer half-lives pose a greater threat

to the environment.


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Chemical Interactions

- Antagonistic interactionone materialinterfere with the effects or stimulates thebreakdown of other chemicals

- Additive reactioneffects of eachchemical are added to one another

- Synergistic reactionone substanceexacerbates the effect of the other


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Measuring Toxicity

Animal Testing - exposing a population oflaboratory animals to measured doses of specifictoxins

Toxicity Ratings- Moderate toxins takes about 1 g/kg of bodyweight to produce lethal dose

- Very toxic requires 10 % of the same amount

- Extremely toxic requires about 1%

- Supertoxic can be lethal in few micrograms


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Measuring Toxicity

Acute vs. Chronic Doses and Effects

- Acute effect is caused by a single exposure

and results to an immediate health problem

- Chronic effect is a result of a single large or

repeated smaller dose with long last or

permanent effect

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Health and Toxicology