As a kid growing up in the 1970s, I can remember my mom pulling up to the filling station and asking for “regular” gasoline. At the time, I didn’t realize what this meant, but as I got older I found out that “regular” gasoline had lead in it; the other option – “unleaded” gas – did not.
Now, as a scientist working for EPA, I have a true appreciation for what lead is and how the next generation of kids can benefit from living in an environment that is cleaner because “regular” gasoline is no longer the norm.
By removing lead from gasoline and tightening industrial emissions standards, EPA has drastically reduced lead air emissions in the U.S.; they declined by more than two orders of magnitude (100 times) between 1970 and 2008. But even with such important progress, by 2008 scientists realized that it was not enough, and that a young child’s cognitive function could be impacted by much lower lead exposures than previously understood. Supported with such science, EPA lowered its National Ambient Air Quality Standard for lead tenfold.
In June 2013, EPA released its most recent review of the science on the health and ecological effects of lead. Scientists who study lead consider it one of the “dirtiest” chemicals because it affects so many different systems in the body. It does this by interfering with molecules called “ions.” When lead exposure affects ion status in the cells, it disrupts how calcium is regulated and how proteins are used for essential bodily functions. This can lead to a wide array of health and ecological effects.
In children, lead exposure can cause IQ reductions and decreased academic performance. Lead can also cause behavioral changes in children, have harmful effects on blood cells and blood producing organs, and may cause decreased auditory and motor function, as well as immune effects. Some of these effects may be irreversible and there is no evidence of a threshold below which scientists can be confident that there are no harmful cognitive effects from lead exposure. In adults, long-term lead exposure can cause increased blood pressure and hypertension, lead to coronary heart disease and affect many other organ systems. Just as lead can harm humans, it can also harm animals and other organisms that live on land and in the water by reducing survival, growth and reproduction, as well as affecting behavior, development and blood producing organs.
In addition to setting standards for lead in air, EPA continues to protect human health and the environment from the harmful effects of lead through a variety of programs. EPA’s assessment of the science on the health and ecological effects of lead underpins these efforts. I am proud to be part of an agency that’s been working for four decades to keep lead out of our air, water, and soil.
To find out more about what EPA is doing to protect the American public from lead exposure, visit the Agency’s lead website at http://www2.epa.gov/lead.
About the Author: Ellen Kirrane is an epidemiologist in EPA’s National Center for Environmental Assessment. She works on Integrated Science Assessments, which form the scientific basis for the National Ambient Air Quality Standards.