5 environmental neurotoxicants are potent health risks

Pediatricians know from their training that chemicals in the environment are important causes of neurodevelopmental and other health problems in children, but clinicians need to keep that information top-of-mind in daily practice and apply it in counseling and evaluation, said Philip J Landrigan, MD, MSc, FAAP.

Landrigan spoke at the 2017 American Academy of Pediatrics (AAP) National Conference and Exhibition on Sunday, September 17, in a session titled “Targeting environmental neurodevelopmental risks: Exposure to 5 key chemical groups is harming our children.” He reviewed the neurotoxic effects of lead, mercury, organophosphate pesticides, combustion-related air pollutants, and polychlorinated biphenyls (PCBs), presented recommendations that pediatricians should make to families for reducing or preventing a child’s exposure to these hazards, and discussed some strategies for identifying environmental chemicals as a cause for behavioral/neurodevelopmental problems.

“It is important to remember that children are at risk every day of being exposed to chemicals in the environment that can damage their brain and nervous system and to remind pregnant mothers that these chemicals can harm their developing baby, too,” said Landrigan, dean for Global Health, Arnhold Institute for Global Health, and professor of Environmental Medicine and Public Health, and of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York.

Environmental exposure to lead has decreased in the United States with the elimination of this chemical from consumer paint in 1978 and from gasoline starting in 1975. The recent water crisis in Flint, Michigan, however, is a stunning reminder that the problem has not disappeared.

Recommended: How to manage an airway emergency

“The situation in Flint is not unique, and the Centers for Disease Control and Prevention (CDC) estimates there are still more than 500,000 children in the United States with levels of lead in the blood that are too high. Based on findings using advanced testing technology that detects injury from very low levels of exposure that were previously thought to be safe, the CDC and also the World Health Organization now state that no level of lead in blood is safe in children,” Landrigan said.

Contaminated fish and shellfish are major sources of exposure to mercury and PCBs. Although fish consumption should be encouraged because of its omega-3 fatty acid content, pediatricians should counsel families about which types of fish are healthy and which that should be eaten in only limited amounts or avoided completely. Listings are available online from various organizations, including the National Resources Defense Council and the Environmental Working Group, and the Monterrey Bay Aquarium.

These lists can be copied and distributed in the office.

To minimize exposure to organophosphate pesticides, parents should be encouraged to talk to people responsible for the care and maintenance of playing fields and grounds at schools and parks and advocate for using integrated pest management instead of chemical pesticides. At home, families should avoid using pesticides for plant and garden care. And lastly, families who have the option and can afford to do so should choose organic foods.

Landrigan also made pediatricians aware that the widely used organophosphate insecticide, chlorpyrifos (Dursban) is now understood to be a potent cause of brain damage in children. Epidemiologic and clinical studies show that exposure in utero is particularly hazardous. The AAP and scientists at the US Environmental Protection Agency (EPA) have recommended a ban of chlorpyrifos.

“Unfortunately, Scott Pruitt, EPA administrator, decided in March 2017 that chlorpyrifos be allowed to stay on the market for another 5 years,” Landrigan said.

Landrigan also noted that air pollutants are the hardest environmental toxins to avoid. “The best way is to choose where you live, but that opportunity does not always exist,” he said. Another strategy is to work with local elected officials and the health department to identify air pollution sources and limit their emissions.

In a child who presents with a learning disability or behavioral problem, pediatricians should consider environmental chemical exposures as a potential cause and explore the possibility through a history. Blood testing and possibly an environmental assessment should be ordered if there is suspicion for lead exposure.

NEXT: Commentary

Commentary

An educational session on environmental neurodevelopmental risks during the 2017 AAP National Conference is recognition that exposure to chemical neurotoxicants is a reality of living in the 21st century. In addition, it reflects growing understanding about the potential harms that chemicals in the environment pose for children and developing babies, says Alan Woolf, MD, MPH, FAAP, professor of Pediatrics, Harvard Medical School, and director, Pediatric Environmental Health Center, Boston Children’s Hospital, Boston, Massachusetts.

“Parents look to their primary care pediatrician as a trusted authority for counsel and advice on numerous topics, including concerns about chemical exposures. Therefore, Dr. Landrigan’s session at the AAP meeting is very germane to pediatricians as they aim to provide the most current and accurate information to patients and their families,” says Woolf.

Next: Does residential 'greenspace' help asthma control?

The information provided in the session is also important for pediatricians who have a responsibility to act as community advocates for public health. In particular, knowing about the risks associated with exposure to organophosphate pesticides and about the safer alternatives allows pediatricians to become involved in initiatives, such as to avoid whenever possible aerial spraying of pesticides in public areas.

Woolf concurs with Landrigan’s advice to pediatricians about ordering a blood test whenever lead exposure is a suspected cause for learning, behavioral, or developmental problems. He adds that if a patient’s history raises concerns about exposure to mercury or polychlorinated biphenyls, pediatricians should counsel the patient and/or family about avoiding further intake of the potential source, and they may also consider making a referral to a subspecialist in toxicology or pediatric environmental health for further evaluation.

-Alan Woolf, MD, MPH, FAAP, is professor of Pediatrics, Harvard Medical School, and director, Pediatric Environmental Health Center, Boston Children’s Hospital, Boston, Massachusetts.