Generations at Risk
How Environmental Toxins May Affect Reproductive Health in Massachusetts
Authors: Ted Schettler MD MPH, Gina Solomon MD MPH,
Paul Burns JD, Maria Valenti
A 1996 Report by Greater Boston Physicians for Social Responsibility (GBPSR) and the Massachusetts Public Interest Research Group (MASSPIRG) Education Fund.
- Of the more than 80,000 synthetic chemicals in commercial use today, only a small fraction have been adequately examined for toxic effects in humans and other life forms;
- Despite limited scientific information, there is solid evidence of the reproductive toxicity of some substances in widespread commercial use including solvents, metals, and pesticides; newly-emerging evidence of the toxicity of others; and important new information about a mechanism of toxicity known but largely ignored for many years - hormone (endocrine) disruption;
- Federal and state regulations are frequently not written or implemented in ways protective of human health and the environment;
- Of industries required to report chemical use, Massachusetts businesses used more than 2.1 billion pounds of toxic chemicals associated with reproductive or developmental disorders from 1990-1994;
- Right-to-know legislation like the federal Toxics Release Inventory and the Massachusetts Toxics Use Reduction Act provide the public with essential information which is rightfully theirs about toxins to which they may be exposed. However, information gaps show that these laws do not go far enough. Since these laws were implemented, there has been a reduction in the environmental release of known and suspected reproductive toxins in Massachusetts;
- In order to protect the public from exposure to known and suspected reproductive toxins, a precautionary and collaborative approach must be used by government, industry, the medical and scientific communities, advocacy groups, and private citizens.
More than 80,000 synthetic chemicals and metals are currently in commercial use in the U.S. The toxicity of most of these is unknown or incompletely studied. In humans, exposure to some may cause cancer, reproductive and developmental disorders, adverse neurological and immunological effects, or other injury. Reproductive and developmental effects are of concern because of important consequences for couples attempting to conceive and because exposure to certain substances during critical periods of fetal or infant development may have lifelong and even intergenerational effects.
Unfortunately, toxicological information is often incomplete. Animal testing usually looks at health effects using one chemical at a time. This strategy fails to provide information about interactive effects which may occur with exposure to more than one chemical. Moreover, animal tests often fail to examine for subtle, delayed, or difficult-to-diagnose conditions. Epidemiological (human) studies are often limited by inaccurate exposure assessments and incomplete information about health out comes. Further complicating matters, the federal government is reducing its support for research and information analysis. Corporate funding is filling the void, providing an opportunity for bias in study design and data interpretation.
Some of the specific synthetic chemicals or metals reviewed in this report are known to harm human reproduction or development. Lead and mercury, for example, disrupt brain development in the fetus. Solvent exposures are associated with spontaneous abortions in female workers. Several specific solvents have additional adverse effects -- glycol ethers and epichlorohydrin damage male reproductive function, and toluene causes birth defects at high levels of maternal exposure. Workers exposed to mixtures of pesticides are at increased risk of spontaneous abortion and birth defects in offspring. Some pesticides, like the fumigant, ethylene oxide, used to sterilize medical equipment, or the fungicide, benomyl, and herbicide, cyanazine, used in Massachusetts agriculture, are identifiable as particularly associated with adverse reproductive outcomes. While the scientific evidence is weaker and still emerging, many other chemicals may also adversely impact human reproduction. Suspects include cadmium, manganese, several solvents including xylene, styrene, and perchloroethylene, and numerous pesticides and plasticizers.
Animal testing reveals that a single dose of a tiny amount of dioxin administered during a critical "window of vulnerability" in pregnancy can lead to life-long health effects in offspring. Men exposed to Agent Orange, an herbicide containing dioxin, are more likely to father children with birth defects. In addition, maternal exposure to PCBs seems to result in developmental delays in children. Dioxin and PCBs are examples of chemicals which appear to derail human reproduction and development by interfering with hormones. Other chemicals which may also be endocrine disruptors in humans are commonly found in consumer products such as plastics, paints, detergents, cosmetics, and pesticides. While the full significance of some of these newly recognized or suspected reproductive and developmental toxins is not yet clear, there is reason for concern about a wide range of chemicals and their potential effects on human health.
Laws which regulate human and environmental exposure to hazardous substances generally take one of two possible approaches -- "better safe than sorry" or "innocent until proven guilty." We believe that a "better safe than sorry," or precautionary approach, should guide risk management and regulatory decisions. This means that the issue of safety should be thoroughly considered before human and environmental exposures are permitted. No hazardous substance should be allowed to slip through the cracks because of a lack of information, time, or funding. Where there is some evidence of human or environmental toxicity, the precautionary approach demands that exposures be avoided or minimized.
Federal legislation which regulates pesticides and pharmaceuticals, for example, intends that manufacturers provide evidence of safety before a product is released for use -- a seemingly cautious approach. But for many pesticides which were in use for years and "grandfathered" when EPA took over the pesticide registration process, safety studies are seriously inadequate. The special review process designed to address these deficiencies will not be complete for years. Moreover, despite the legislative intent, animal testing used to support an application for new pesticide registration currently fails to examine adequately for subtle and delayed toxicity. Furthermore, the registration process for pesticides does not account for interactive or cumulative effects of multiple exposures that individuals are likely to experience in real-world situations. And there is no comprehensive evaluation of the impact such chemicals may have on the environment generally.
But, for most industrial chemicals, there is no absolute requirement for advance demonstration of safety before the product enters the commercial market. For example, under the Toxic Substances Control Act, the only legislation which addresses chemicals not covered by other laws, the Administrator of the Environmental Protection Agency must have reason to believe that a substance poses unreasonable risk to health or the environment before proposing controls -- i.e., the chemical is "innocent until proven guilty." Though the law states that the Administrator should have adequate data on which to base a decision, there are no standard testing protocols which are required before the chemical is released for use. And, with chemical manufacturers announcing more than 1,000 chemicals for production annually, the political and economic pressures to avoid thorough safety review are enormous. Appropriate screening and testing have never been practical possibilities under existing law. Moreover, industry has frequently abused "confidential business information" provisions in the legislation, effectively concealing the nature of industrial chemicals to which many people are exposed.
The federal Toxics Release Inventory (TRI) and the Massachusetts Toxics Use Reduction Act (TURA) are two landmark laws that require public disclosure of environmental releases and use of listed chemicals by large industrial operations. They are the centerpieces of right-to-know legislation. Each is based on the fundamental principle that individuals have the right to know the identity of substances to which they are or might be exposed. Because of these laws, information is now available throughout the country about emissions of some toxic substances from selected industrial sources. In Massachusetts, information about chemical use is also available.
Environmental releases of chemicals with some evidence of reproductive toxicity have declined substantially since reporting requirements were established in Massachusetts. However, the amount of these chemicals incorporated into products has not changed significantly. The amount used tends to fluctuate with economic cycles. To the degree that right-to-know laws have contributed to the decrease in emissions they have been useful for protecting public health. However, their ultimate validity rests in their recognition of the public's right to know, irrespective of incentives they provide for reducing toxics use and releases. Such laws ensure that the public has the information required to make policy decisions and give individuals access to information they may need to protect themselves. We support efforts to expand each of these laws to include additional industries and hazardous substances and to make the data more readily available and understandable to the general public.