exposure assessment

Human Health Risk Assessment—What it’s all about

Three images arranged horizontally: grade school students in classroom; girl with arms raised; bicyclists at sunrise

By Kacee Deener 

Scientists need to be able to describe—in a way everyone can understand—what we do and why it’s important.  That’s one reason I’ve decided that I need to strengthen my “elevator speech” about what I do (human health risk assessment).  I will be writing blog posts over the next several weeks trying to explain human health risk assessment in plain language.

For this first post, I’ll introduce the concept of risk and explain why human health risk assessment is important.

Risk is something we all understand.  In fact, we all assess risk every day.  What is the risk of swimming in the ocean on a clear day?  Does the risk change if there are jellyfish? How about an approaching storm?  A shark swimming nearby?  We all understand these types of risk calculations at a very intuitive level.

Human health risk assessment isn’t so different.  It’s a process of characterizing the nature of an environmental risk (in many cases, a chemical exposure) and determining how large that risk is to humans.  It consists of four steps: (1) hazard identification, (2) dose-response assessment, (3) exposure assessment, and (4) risk characterization.  I will discuss each in future posts.

So why is human health risk assessment important?  Well, chemicals are a part of life.  Some exist naturally; some are made by humans and can be released to the environment.  They bring benefits to our lives, but like most things, they also come with risks.

Let’s consider a hypothetical example.  Suppose a factory produces something you use every day.  To make this product, the company uses several different chemicals, and some chemicals are produced during the manufacturing process as byproducts.  Some are released to the air and water and may get into the soil.  Let’s say this industrial site is located next to a river that leads to your local drinking water plant.  Are any of the chemicals in that water?  Are the levels safe for you to drink?  What about your child? What levels of the chemicals are safe for you to breathe?

Human health risk assessment helps answer questions like these.  It is a tool that helps local, state and federal governments make decisions about what levels of chemicals can be in drinking water; what additional controls are needed to keep levels emitted to the air at a safe level; and what levels need to be achieved to clean up a contaminated site.  From a public health perspective, this is pretty important stuff.

In the coming weeks, I’ll be posting more about EPA’s human health risk assessment work. Stay tuned for those posts, but in the meantime, you can learn more by going to http://go.usa.gov/KhCJ.

About the Author: Kacee Deener is the Communications Director in EPA’s National Center for Environmental Assessment.  She joined EPA 13 years ago and has a Masters degree in Public Health.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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EPA-Expo-Box: A Novel Innovation for Risk Assessors

By Dahnish Shams

Illustration of a toolbox

Click on the image to go to the EPA-Expo-Box website.

As a college student, I always found Wikipedia to be one of the simplest, yet most innovative resources created in the last decade. Wikipedia’s ability to compile and aggregate different information in a single spot on the internet makes it a unique web resource to accomplish any number of tasks across a wide variety of disciplines and settings.

Now—post graduation and working as a student contractor in EPA’s Office of Research and Development—I’ve found out that EPA scientists have developed their own innovative, encyclopedia-like resource for exposure assessment information. Links to databases, models, guidance documents and other resources are organized by topics such as exposure assessment approaches, chemical classes, environmental media, routes of exposure, life stages and populations, and more.

This new website, EPA-Expo-Box (short for EPA Exposure Toolbox), has compiled links to more than 800 exposure assessment tools all in one user-friendly format.

For example, imagine a scientist examining an outdoor air or water pollutant. This scientist could use EPA-Expo-Box’s Media Tool Set to help identify information needed to assess how this pollutant may be interacting with the environment, and tools needed to estimate exposures among the people who may come into contact with the air or water. This scientist could access resources on potential sources, fate and transport, or measured concentrations of the chemical in the air or water. With 800+ resources readily in hand, risk assessors can make informed scientific decisions to better protect the public and the environment from harm.

Prior to EPA-Expo-Box, there were no comprehensive publicly available resource for exposure assessment tools and information.  Recognizing this need, EPA scientists set out to design an online “one stop shop” for   resources that an exposure assessor may need. This free resource fills a specific niche in the risk assessment community. As an interactive scientific resource, it contains links to databases, models, guidance documents, and reference materials, along with step-by-step assistance for conducting exposure assessments to help guide users through the exposure assessment process.

Because it is completely online, users can access all of the tool sets at the touch of a button on their laptop, tablet, or smartphone. This versatility gives EPA scientists and others access to exposure assessment information regardless if they are in the field or in a laboratory. Like any good resource, EPA-Expo-Box is simply a handy tool to have when you need it most.

The other advantage of an online-only platform?  When new resources become available, updates can be made quickly and easily. No longer will users have to wait for the next edition or version to get the most up to date information. The dynamic nature of EPA-Expo-Box is increasingly crucial in the ever changing field of risk and exposure assessment.

Day in and day out, it is versatile and dynamic innovations like EPA-Expo-Box that better help EPA and others access information they need to more effectively evaluate potential risks to human health and the environment in the communities in which we all live and work.

About the Author: Dahnish Shams is a student services contractor working with EPA’s National Center for Environmental Assessment in communications.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.