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Exposure Pathways

What is an exposure pathway?

An exposure pathway is the way hazardous substances move from their source to people. Exposure pathways help us learn about our potential exposure to hazardous substances and what we can do to prevent them.

Watch the video to learn about exposure pathways!

Who is most at risk?

Exposure to hazardous substances can cause more harm to some people compared to others.  People who are more likely to experience serious health effects include:

  • Children
  • Pregnant women
  • Older adults
  • People with certain medical conditions
  • Babies and toddlers
    • They often touch and put things in their mouth, which can expose them to harmful substances. These substances can affect their growth and development.

What to consider if you have been exposed to a hazardous substance.

Being exposed to a hazardous substance does not mean it will make you sick. Whether the exposure is harmful to your health depends on:

  • How easily the substance moves through the air, soil, surface water, groundwater, and drinking water.
  • How harmful to health the substance is.
  • How much of the substance got on or in the body.
  • How long the exposure lasted.
  • The sensitivity of the person exposed.

How do I know if there is a risk of hazardous substance exposure?

To determine if there is risk of exposure to hazardous substances, consider these scenarios. If all these scenarios are true; you have found a complete exposure pathway.

Is there a source of contamination?

Hazardous waste may have come from various sources throughout the years. This has properties capable of having a harmful effect on human health or the environment. Hazardous waste can include industrial manufacturing process wastes to batteries. This may come in many forms, including liquids, solids gases, and sludges.

Look for things nearby that could be releasing hazardous substances:

  • Poorly managed landfill
  • Illegal dumping
  • Spills
  • Broken pipes
  • Emission stacks
  • Known hazardous waste sites
  • Metal plating facilities
  • Dry cleaners
  • Gas stations
  • Nail salons
  • Chemical manufacturing plants
  • Poorly managed storage drums
  • Waste piles
  • Industrial or waste management locations

Some sources could come from nature, for example, metals in soil. The amount and kinds of metals in soil depend on where you live. Some activities can increase metal levels in soil and release metals into the air and water.

Is it possible for the hazardous substance to enter the environment?

If a substance is safely stored, there is little chance of people being exposed to it. But if it is released into the environment (air, water, soil), someone may come into contact with it. This can happen in places like homes, daycares, schools, and restaurants, not just industrial and waste sites.

Can the hazardous substance move to other places?

Hazardous substances can move from one place to another where people live, work, or play. They can travel through the air, soil, surface water, groundwater, sediment, sludge, and even food or drink products. For example, you can carry hazardous substances from soil on the bottom of your shoes into your home.

How can people be exposed (route of exposure)?

People can be exposed to hazardous substances through breathing, swallowing, or touching. You can absorb hazardous substances through the skin, eyes, nose, or mouth. This can happen when you swallow contaminated food or liquids. It can also happen if you have hazardous substances on your hands and you touch your food, eyes, nose, or mouth directly. 

What are the three types of exposure pathways?

  • Completed Pathway: Someone has been exposed to a hazardous substance in the past or present.
  • Potential Pathway: When people have been exposed to a hazardous substance in the past, might be exposed currently, or may possibly be exposed in the future.
  • Eliminated Pathway: Exposure to hazardous substances is not expected to happen. This could be because the hazardous substance once existed but was removed.

What are some daily habits that can help me prevent exposure to hazardous substances?

  • Maintain and test your private well yearly.
  • Wash hands and produce before eating.
  • Keep pets clean and wipe their paws before they enter the house.
  • Remove shoes before walking inside.
  • Dust with a wet cloth inside of dry dusting.
  • Vacuum with a HEPA filter instead of sweeping.
  • Use a portable HEPA air filter or the highest-grade filter safe for your HVAC system.
  • Garden in non-contaminated soil or in a raised bed using store-bought gardening soil.
  • Limit the use of toxic chemicals for cleaning, pest control, and lawn maintenance. Make sure you follow all directions on the labels.
  • Do not eat fish from areas under a fish consumption advisory.
  • Do not drink from any stream or lake.
  • Do not trespass onto areas where known contaminants are present.

Additional Resources:

Environmental Protection Agency: Cleanups in Texas

Environmental Protection Agency: What is a HEPA filter?

Texas Department of State Health Services: Texas Fish Consumption Advisory Viewer

Texas Commission on Environmental Quality: Drinking Water Quality

Texas Commission on Environmental Quality: Superfund Sites in Texas

Texas Well Owner Network