3/5/25 - Public Health and Environmental Justice

How are environmental benefits and burdens distributed?:

• Environmental Justice is the idea that no community should bear more environmental burdens.

Responding to issues of environmental justice:

• One important environmental justice tool that can empower communities.

What is the study of environmental health?:

• Toxins are poisonous substances that cause illness/death.

• We now have the field of environmental health that assesses how the environment impacts human health.

Epidemiology:

• Study of distribution/determinants of what causes diseases, how they occur/are distributed.

Toxicology:

• Studies the negative effects of substances on an organism.

Public health:

• The study/practice of protecting/improving the health of people.

How do microorganisms make us sick?:

• Humans contain more resident microorganisms than human cells.

• Pathogens are microorganisms that cause illness when they reside in our bodies.

• Biological hazards are organic substances that pose a threat to the health of living organisms, can cause infectious diseases, and account for one in four human deaths.

What are the major types of biological hazards?:

• Respiratory infections are infectious diseases that affect the lungs and airways.

• These infections have been the leading cause of sickness and death worldwide pre-COVID.

• Diarrheal diseases are caused by pathogens that affect the digestive processes.

• Blood-borne pathogens are infectious microorganisms in human blood that can cause disease.

Where do these pathogens strike?:

• Some pathogens are more prevalent in low-income countries because of crowding and unsanitary conditions.

• Lack of access to clean drinking water/sanitation systems leads to diarrheal diseases.

Future risks:

• Global mortality rates from infectious diseases are decreasing due to improvements in public health, education, and sanitation.

• Health professionals worry about drug-resistant pathogens.

Herd immunity:

• Public vaccinations play an important role in environmental health.

• Herd immunity is when members of a population are unlikely to become infected by a pathogen because most of the population is either vaccinated or has been previously infected.

  • When vaccinations are widespread, they protect a small number of people unable to be vaccinated.

What does it mean when something is toxic?:

• Chemical hazards are chemicals linked to immediate/delayed health effects after exposure.

• Toxic chemicals can cause injury or death.

• Toxins can be addictive.

Risk factors:

• All chemicals can be toxic depending on the amount of exposure.

• Toxicologists measure risks in terms of percent mortality of exposed populations, usually identifying the dose required to kill half the individuals.

• Individuals respond differently to chemicals, making some people more/less vulnerable to the same concentration.

How can I be exposed to toxins?:

• The fastest way for a substance to be absorbed into the body is through inhaling it, and volatility describes the tendency of a chemical to evaporate in the air.

• Volatile organic compounds are gases related through evaporation or incomplete combustion of fossil fuels or other organic compounds. These can be found in everyday items like paints/nail polish.

• Persistent organic pollutants are chemicals that resist breakdown through chemical reactions, biological processes, or exposure to sunlight.

Where exposure occurs:

• More likely to occur in populations of color.

• Food consumption patterns among poorer communities have resulted in high levels of chemical exposures.

• Workplace exposure is disproportionately high among lower-wage workers and people of color.

How do we manage risks associated with toxins?:

• Risks are managed through governmental regulations, which can differ between regions.

• In the US, the EPA regulated new chemicals.

• “Burden of proof” - Who is responsible for providing proof of safety or hazard: the manufacturer or a governmental agency?

  • Precautionary principle: needs to prove chemical is safe before using it widely (EU).

  • When there is uncertainty as to harm - benefit of doubt favors the manufacturer (US)

Climate change and environmental health:

• Floods occur when water inundates land that is normally dry.

• In coastal areas, storm surges can cause flooding.

• Human land use decisions directly influence flood damage.

• Heat waves are periods of high heat that can be deadly.

• Heat waves can cause water shortages and drought.

Environmental justice - where are vulnerable communities located?:

• Most vulnerable areas are lower-income, poorer communities.

• Studies have shown that lower-income communities have more traffic-related injuries and fatalities due to fewer sidewalks, as well as having a high number of major intersections and 4-way stops.