8.14: Pollution and Human Health

Learning Objective: Identify sources of human health issues that are linked to pollution

Essential Knowledge:

  • It can be difficult to establish a cause and effect between pollutants and human health issues because humans experience exposure to a variety of chemicals and pollutants

  • Dysentery is caused by untreated sewage in streams and rivers

  • Mesothelioma is a type of cancer caused mainly by exposure to asbestos

  • Respiratory problems and overall lung function can be impacted by elevated levels of tropospheric ozone.

Routes of Exposure & synergism:

It’s difficult to establish exactly how toxic different pollutants are to humans because we have so many routes of exposure to so many different pollutants, that studying the effects of just on pollutant is difficult.

Routes of exposure:

  • Ways that a pollutant enters the human body

    • Lead → water pipes & paint chips

    • Mercury →seafood (tuna)

    • CO → indoor biomass combustion

    • PM -. pollen, dust, etc

    • Arsenic -. rice, groundwater

Synergism:

  • The interaction of two or more substances causes an effect greater than each of them individually

    • EX: asthma caused by PM from coal power plants and COVID-19 damaging lungs

    • carcinogenic effect of asbestos combined with lung damage from smoking

  • Synergisms make it especially hard to pinpoint the exact effects of one specific pollutant on humans.

Dysentery:

Bacterial infection caused by food or water being contaminated with feces (often from sewage release into rivers & streams used for drinking water)

  • Causes intestinal swelling and can result in blood in feces

    • Results in severe dehydration due to diarrhea (fluid loss)

    • Kills 1.1 million people annually, mostly in developing countries with poor sanitation and limited access to water filtration

  • Can be treated with antibiotics that kill the bacteria causing the infection and access to treated/filtered water that rehydrate

Mesothelioma (asbestos):

A type of cancerous tumor caused by exposure to asbestos, primarily affecting the lining (epithelium) of the respiratory tract, heart, or abdominal cavity

  • Asbestos exposure comes primarily from old insulation materials used in attics, ceilings, and flooring boards; when the insulation becomes physically disturbed, asbestos particles are released into the air & inhaled

  • Removal of asbestos-containing insulation material should be done by professionals with proper training and equipment that protects them from inhaling the asbestos

    • The area where asbestos is removed should be sealed off from other areas in the building and well-ventilated during the removal process

    • Insulation without asbestos should be used to replace it

Tropospheric Ozone (O3):

Worsens respiratory conditions like asthma, emphysema, bronchitis, COPD

  • Limits overall lung function

    • irritates muscles or respiratory tract causing constriction of airways & shortness of breath

    • Irritates eyes

  • Sources: photochemical breakdown of NO2 (car exhaust, coal, and NG combustion)

ONLY HARMFUL in the troposphere (beneficial in stratosphere)