Toxins’ long-term effects on humans will be studied
ALBANY, N.Y. - New York scientists have been awarded a $5 million federal grant to study long-term human exposure to chemicals in the environment.
Chemicals can pop up in plastic bottles, toys, medical equipment, pillows, and upholstery. Scientists are looking to see if micro-amounts of environmental compounds that humans are exposed to will stay in the body, or have lasting effects. California and Washington state also have been awarded grants.
Scientists will take samples of urine, blood, and saliva, and even test the breath of subjects to get an idea of what is in their bodies. They will measure how much and what kinds of chemicals are flowing through blood and fat tissue. Some of those chemicals are metabolized and leave the body, while others persist.
“The fact that we have, and can measure, some of these chemicals in people does not necessarily mean that they cause disease, and we’re very careful to mention that,’’ said Dr. Kenneth Aldous, director of the Division of Environmental Health Sciences at the state Department of Health’s Wadsworth Center laboratories. “However, the fact that they are in our bodies and that they may be increasing - which is something biomonitoring can tell us - may be important down the road, measuring their correlation with disease.’’
New York scientists will study the toxins in people’s bodies in different parts of the state and compare them to national data. Some populations are being watched for specific exposures. For example, the densely populated New York City area could have more people exposed to car exhaust, while Asian communities may have higher mercury levels because of their frequent consumption of fish.
Scientists still are exploring what effects various chemicals have on humans, but three that are being closely watched are chemical compounds known as phthalates, Bisphenal A, and PBDEs. The human health effects of low levels of these chemicals are unknown, but they have been shown in animal studies to disrupt several systems.
Phthalates are used to soften plastics and have been linked in some studies to reproductive problems. They are found in toys, shower curtains, flooring, and medical equipment.
Bisphenal A is used in some plastic water bottles, dental sealants, and the protective coatings of metal food cans. Some scientists believe exposure may harm the reproductive and nervous systems and possibly promote prostate and breast cancers.
Chemical flame retardants called polybrominated diphenyl ethers, or PBDEs, are often used in upholstered furniture, automobile components, and home electronics. PBDEs are manmade chemicals used in goods since the 1970s. They have been associated with impaired liver and thyroid function and other health effects.
Scientists want to take a snapshot of the environmental chemicals that people carry right now, and track them so that scientists have a timeline to learn if these compounds increase over time.
“If we don’t measure the levels of these compounds at some point in time and get an idea of what our body burdens are, we don’t know if these compounds are changing in the environment, and we don’t know if we’re being exposed at a larger or lesser extent,’’ Aldous said.
One of the classic examples of environmental toxins is lead. Lead poisoning can cause irreversible learning disabilities, behavioral problems, and, at very high levels, seizures, coma, and death.
As more was learned about the health risks associated with lead exposure, its use was minimized or eliminated in many common materials, including gasoline and paint. As a result, scientists find much lower levels of lead in children now than those from decades ago.