The number of industrial chemicals in widespread use recognized to cause childhood brain impairments has more than doubled since 2006, scientists said Friday.

Researchers at the Mount Sinai Hospital and Harvard School of Public Health cited six broad groups of toxins in 2006 as having a direct impact on human brain development. Now, they have identified another six, which include metals and inorganic compounds, pesticides and dangerous solvents.

Based on their examination of chemicals that are widely used — but untested for human safety — the scientists concluded that fetal and early childhood exposures have grown into a silent pandemic of neurodevelopmental disorders, such as autism, attention-deficit hyperactivity disorder, dyslexia and even losses in IQ points.

Some of the brain-damaging compounds, they say, waft through the air of countless homes as house dust.

“These are chemicals that Americans are exposed to on a regular basis,” said Dr. Philip Landrigan, chairman of preventive medicine at Mount Sinai’s Icahn School of Medicine in Manhattan and director of the Children’s Environmental Health Center at the hospital.

In the first study Landrigan and colleagues named arsenic, arsenic-based compounds, lead, methylmercury, toluene and polychlorinated biphenyls — PCBs — as key brain-damaging culprits. That list was culled from a longer […]