Foggy tree rainforest

What environmental factors affect health?


It’s not just what you’re exposed to that matters

The truth is, it’s challenging to pin down exactly what factors cause an environmental health problem. Health problems related to the environment are complex and develop for a variety of reasons, including how likely a person’s genes are to develop a disease or condition (scientists call this genetic susceptibility). What we do know is that an environmental health problem is likely linked to physical, biological and even economic factors.

The air we breathe, the water we drink, the food we eat and the homes, buildings and neighborhoods we live and work in can all contribute to environmental health problems, sometimes by disrupting how the body works. Some potential sources of environmental health problems include:

  • Air pollution: From car exhaust to wildfire and e-cigarette smoke to ozone, pollution is a mix of natural and manmade substances found both indoors and outdoors.
  • Flame retardants: There are hundreds of chemicals used in consumer products from electronics to furniture that help prevent the spread of fires.
  • Lead: Old paint, contaminated soil and water, pottery and even house dust are a few ways people are exposed to this metal.
  • Nanomaterials: Engineered nanomaterials are a concern because particles are tiny and used in many consumer materials, structures and devices.
  • Perfluorinated chemicals: These compounds help reduce friction and also are used to make products resistant to stains, water and grease.
  • Smoke: A single cigarette is chock full of hundreds of chemicals including arsenic, formaldehyde and lead.
  • Pesticides: These chemicals kill, repel or control pests from weeds and fungus to insects.

Scientists suspect many of the things we’re exposed to in our environment are related to health problems like cancer, asthma or Parkinson’s disease. But it’s not just what we’re exposed to that matters: A potential environmental impact on health can lead to a cascade of biological events in the body that alters the way it works – but these changes can be bad or good, and are highly individual depending on genes and circumstances.

Child playing in park

For example, obesity is related to genes and exposure to certain chemicals. But how much activity a person gets every day can be a bigger predictor of whether or not someone is a healthy weight. That means availability of parks, affordable healthy food and even sidewalks are important environmental factors in helping people keep their BMI in check.

While exposure to certain substances is bad, an environmental health problem also can be related to not getting enough of something good. Autism has been linked to pesticides but research suggests not getting the recommended amount of folic acid during pregnancy could contribute to it, too. Folic acid is recommended for all women planning a pregnancy to prevent neural tube defects in babies but it can also protect against autism.

Another factor to consider is economics, which plays a crucial role in the way disease, illness and disability plays out over the long-term. Autism, for example, has been associated with an immune response in mothers that scientists hope someday could help identify the condition before a baby is even born. Very early intervention could help children with autism – but only if their families have access to quality health care.  

Inequality & the burden of disease

People who are socially and economically disadvantaged carry a heavier burden of disease. Below is a photo gallery with an infographic that explains how structural racism and health disparities have played out around the COVID-19 pandemic in the United States.