The recent story on a proposal to limit the use of synthetic pesticides in South Portland (“Plan to ban pesticides: A model or a mistake?”, April 11) offers an overview of the differing perspectives on proposed pesticide ordinances. It also raises the significant issue of how both federal and state agencies are not doing enough to ensure that commonly used lawn and garden products are safe.

But this is just one part of a larger and much more ominous problem: the failure over decades of state and federal government to protect citizens from the short- and long-term risks of exposure to literally thousands of hazardous chemicals all around us.

Toxicity to children (and, to a greater extent, dogs) from lawn and garden pesticides is just one aspect of the danger. Tons of widely used chemicals such as glyphosate, the active ingredient in the weedkiller Roundup and nitrogen-rich fertilizers eventually reach Casco Bay, contributing to overgrowth of green algae and mass die-offs of phytoplankton, which can adversely affect fish and shellfish. Growing public concern surrounds the use of neonicitinoid pesticides, which are closely linked with declining numbers of bees and other pollinating insects, bats and other species further up the food chain.

The 1976 Toxic Substances Control Act, a federal law conceded to have been largely shaped by the chemical industry, has been a toothless, sleeping watchdog. During the past 40 years, it is estimated that over 80,000 synthetic chemicals have entered into widespread use in industry, household products, personal care items and myriad other uses; newer chemicals are being added at an estimated rate of over 700 per year. Only a small fraction have been adequately tested and even fewer are adequately targeted by meaningful restrictions or outright bans on their use.

Alarmingly, widespread testing of umbilical cord blood reveals that is possible to detect over 200 synthetically produced chemicals and their breakdown products. In adults, evidence of these same chemicals can also be found in blood, urine, semen and other body fluids.

A wide spectrum of problems are correlated with exposure to synthesized chemical toxins, as well as to many other substances long recognized as harmful, such as lead, mercury, arsenic, dioxin and radon. Many public health experts attribute the rising incidence of various cancers, infertility, birth defects, lowered IQ, attention-deficit hyperactivity disorder and behavior and learning problems to increasing exposure to the toxins that are everywhere in our environment.

Children are more vulnerable to any type of poisoning than are adults, because of their higher metabolism and respiratory rate, greater surface-to-mass ratio and the tendency for toddlers to crawl across lawns and floors, mouthing whatever they think looks interesting. There are also critical periods in utero and during early childhood when their developing nervous systems are more vulnerable to disruptive influences.

Moreover, their longer lifespan means children may continue to accumulate toxic chemicals in their bodies far longer than adults. The presence of even small amounts of endocrine-disrupting chemicals at critical periods of embryonic development may contribute to birth defects in male genitals, and possibly later infertility or other reproductive problems. Such long-term adverse effects escape detection during short-term testing.

Research has shown a clear connection between exposure to some of these hormone-mimicking chemicals and marked obesity in rats raised on the same diet as matched controls, suggesting that environmental toxins – as well as more obvious factors such as overeating and inactivity — may be insidious contributors to the current national epidemic of obesity.

Bills intended to replace the Toxic Substances Control Act have been put forward in the U.S. Senate and House of Representatives, with conference committees now working to integrate these into a meaningful bipartisan consensus. Inevitably, chemical industry lobbyists will be attempting to weaken or dilute any final version. It is thus a crucial time for our congressional delegation to hear from Maine citizens and environmental groups seeking stronger protective action.

When writing or calling the offices of our senators and representatives, urge their support for provisions in any new chemical legislation that will:

• Compel the Environmental Protection Agency to identify and test significant numbers of “chemicals of high concern” (chemicals proven to cause serious health concerns) within a specific time frame.

• Ensure that the language of any new legislation does not effectively invalidate safeguards already in place in Maine and other states with progressive toxic control laws (such as the Kid-Safe Product Act, banning bisphenol-A in child products).

James H. Maier, M.D., of Scarborough is a longtime member of Maine Physicians for Social Responsibility.