Legislators will soon consider a bill to protect our children from dangerous toys and other products (such as phthalates in IV bags in hospitals) from every country, a problem far more prevalent than Chinese lead paint poisoning. The bill would establish a registry where citizens may gain some initial insight into the more dangerous chemicals that show up in ongoing testing. Maine may again lead the nation as the Feds are frozen in their tracks by industry and politics.

This is a perfect example requiring the “precautionary principle,” a restatement of the key point in the ancient Hippocratic Oath “Primum non Nocere,” which means, “Above all, do no harm!” The precautionary principle means that all chemicals must be thoroughly and rigorously proven safe first, beyond any reasonable doubt, before people and our children are subjected to them.

Unfortunately, industry usually is clueless about the negative effects of powerful products, even on common experimental animals, not to mention human beings. Even testing done on humans is short term, and privately funded, so it can be quickly discarded if unflattering. There are some 80,000 chemicals used in industry today, and every year 3,000 more join the ranks with almost no scrutiny, unless they are pharmaceuticals given directly to patients. The official chemical in a product is often part of a mixture of close cousins being too closely related to be purified, even by very expensive techniques.

Human studies are generally on healthy adult white males, never pregnant women and fetuses (remember Thalidomide?). They generally look retrospectively for simple physical markers such as cleft palate or heart murmurs, rather than much more important (and harder to spot) early developmental markers.

Fetuses and kids are far more vulnerable to very subtle and focused, but crippling, learning disorders that can cause a lifetime of family pain. Some of the better known of these are ADHD, Oppositional Defiant Disorder, Asperger’s Syndrome and autism. Other effects such as endocrine disruption, carcinogenesis and other immunological effects are rarely covered. Many common chemicals are felt to have adverse effects in multiple animal systems at seemingly low “normal exposures,” sometimes even worse effects at lower doses than at higher doses.

Each of 30,000 genes encodes one or several proteins that interact with many other genes and proteins, forming the “proteome,” a seething soup of at least 100,000 proteins, which exceeds even 3 billion DNA base pairs in its complexity. Proteins transport materials into and throughout our bodies, and convert food into energy. They enfold and protect the graceful DNA double spiral staircase. They weave delicate spindles that pull chromosomes into daughter cells after division. On immune system cell surfaces, they recognize and help engulf invading microbes. They help us perceive our environment and survive through our five special senses.

One of the most amazing things genes and proteins do is control brain development. The brain does not just start out as a single cell dividing and growing ever larger. Brain cells actually move around in the embryo. Some cells are killed by others or commit suicide. They send out axons and dendrites that hook up with other very specific neurons, which are often many inches away.

All these actions happen at very precise times, measured in single days or even hours – called “windows of vulnerability.” Cell surface proteins and their outgrowing axons and dendrites must continually react to minute traces of messenger chemicals released by other brain cells that tell them where they are and where to go.

Fetal brain development is like a symphony with a hundred thousand instruments. Each must come in at the perfect time and the perfect pitch or you get a damaged child. This damage is detected by sophisticated psychological tests, such as “The Boston Naming Test.” These children often look superficially normal but have problems with hearing or motor skills, and later problems with language, attention and memory. They are often marginalized, ending up in special ed, prison, on welfare rolls or the street.

A fascinating new area of study is “epigenetics” which has shown that our genes may be modified by tiny chemical groups added onto DNA base-pairs by early exposure to environmental chemicals. This is a different mechanism from radiation, which actually changes the DNA permanently. Epigenetic changes may be transmitted to the adult organism over a lifetime and last for more than one generation.

The only thing more fascinating than what we know about living things is how much we don’t know. Let our leaders know it’s time to start protecting our children now!

Paul Averill Liebow, MDFACEP, a member of the Maine Chapter of Physicians for Social Responsibility, lives in Bucksport.