Thyroid-Disrupting Chemicals in the Home and How to Avoid Them

Much like the hand, body, and facial signals used by an orchestra conductor to ensure a great performance by the symphony, hormones are the signals that ensure healthy structure and function of the human body. If the conductor mistimes those signals — or comes on too fortissimo or lento — he can't go back and redo the performance from where the mistake occurred. Similarly, our butterfly-shaped gland in the neck, the thyroid, plays a crucial role in maintaining multiple organ systems.

Take the brain, for example. We've known about congenital hypothyroidism for decades; we screen newborns for this condition because it's eminently treatable. Without supplemental thyroid hormone, children with this condition suffer severe intellectual disability.

We now appreciate that the fetal thyroid gland doesn't become fully functional until the middle of the second trimester, and that the baby relies on mom's thyroid hormone until then. Even subclinical hypothyroidism, in which women have normal thyroid hormone levels but elevations in TSH, can produce cognitive deficits and even attention-deficit/hyperactivity disorder or autism.

The mistakes are costly. Besides the lost economic productivity, neurodevelopmental disorders require lifelong care in addition to intensive behavioral and educational therapy. One estimate of the lifetime societal cost of autism is as high as $3.6 million.