Today, almost 500 synthetic chemicals - most created since World War II-are detectable in human tissues. Pesticide residues, for example, were found in the urine of nearly all children examined in a Minnesota and Washington study. PCB's, dioxins, furans, nicotine, flame-retardants, metals, solvents, and some pesticides are found in human breast milk. The discovery of lead concentrates in babies' teeth prompted further tests of its effect on learning, intelligence and behaviour. Following nearly 25 years of debate, lead was eventually banned from petrol and paints. This history suggests that our bodies may be storing more chemicals than we can now detect. It also suggests that once health risks are recognized, exposures may continue for generations while scientists and lawyers debate what should be done.

Most EPA regulations have resulted from the study of single chemicals. Yet humans are most often exposed to chemical mixtures. And decisions regarding how to regulate single chemicals have often been delayed by litigation or the search for stronger evidence for decades. Arsenic, radon, lead, DDT, and hundreds of other air and water pollutants and food contaminants provide examples of protracted regulation. The single chemical focus together with routine delays in regulation leaves the government's capacity to protect our health from environmental hazards in serious question.

Given this complexity, what should be done?
Governments need to become more strategic. They should concentrate on the most potent chemicals, the most concentrated exposures, the chemicals we are most likely to encounter, and mixtures that could combine to produce additive or synergistic effects. They should be especially careful to control persistent chemicals that may accumulate in the environment and our bodies. Help is especially needed from governments and corporations to identify what is hazardous. Threats are often hard to recognize, undetectable to human senses, and sometimes deliberately disguised. Laws protecting trade secrets, confidential business information and privacy may all inhibit public understanding of environmental risks our health.

The simplest solution is to keep risky substances out of the environments where we live, learn, play and travel. The following pages attempt to provide a sense of what environmental hazards are worth worrying about, and what we can do to provide greater protection for children and ourselves.

Uncertainty and Toxicity Testing Tens of thousands of chemicals have not yet been fully tested for their potential to harm human health. Fewer than 1% of pesticides used on crops, forests, paints, fabrics, lawns, golf courses, in schools, hospitals, and homes (of nearly 20,000 separate products) have been tested to understand their potential to harm children's developing nervous systems. We should demand tests capable of identifying these hazards. Significant progress will be made in toxicity testing over the next several decades. But if history is our guide, the results will not likely be translated into changes in government policies or products in the marketplace until today's toddlers are having families of their own. Even if the Government gives the EPA power to act, many legal and scientific challenges will likely delay implementation by federal agencies, as they have in the past.

Allowing small levels of contamination in food, water and air rests on the presumption that a threshold of harm is well understood. Recent evidence suggests that chemicals may affect the endocrine, immune and nervous system even at very low doses. Some chemicals behave like or block human hormones. Some sensitised individuals experience severe allergic reactions to some substances (such as peanuts or fish) at exceptionally small doses. And others experience a heightened immune response to diverse chemicals-a condition known as Multiple Chemical Sensitivity. Chemical effects on the immune system have rarely been studied prior to their widespread use in commerce, or release to the environment as pollution or wastes.

The food supply is increasingly international, as juices, oils, grains, meats, fish, fruits, and thousands of other processed foods are imported from other nations each year. These trends increase the need for vigilance against food contamination, increase foreign products in our markets, and introduce new chemicals into the environments. Our food production and distribution system is now so complex, international, and decentralized that it is vulnerable to accidental contamination and sabotage. South Africa is still a major user of DDT in crop production and insect pest control.

Air
Most estimates of asthma prevalence range between 7-9%. The background burden of respiratory disease demands that we reconsider management of air quality in a fundamental way. Experts in health are increasingly concerned about indoor air quality. Australian children can spend up to 80-90% of their time indoors, on average. Architectural design, building materials, finishes, and furnishings all influence indoor air quality, and respiratory health. The intentional release of fragrances in cleansers, cosmetics, candles, incense, and deodorizers introduces many additional synthetic chemicals to indoor air and most have not been tested for their effect on health. Poorly ventilated heating appliances, such as wood stoves, and tobacco smoke pose a serious threat to respiratory health. Tighter, more energy efficient building designs reduce the exchange between indoor and outdoor air, and may result in the build-up of chemicals that could cause reactions among sensitive children. Indoor cleaning practices may also introduce hundreds of chemicals - including solvents and other volatile organic compounds - into the environments and our lungs.

It is not clear that outdoor air quality is improving where we spend our time. Perhaps it is getting cleaner where federal and state monitoring facilities are located, however this conclusion depends on what is measured, and how the measurements are averaged. Regulators are required by current law to average pollution across time, and as averaging periods are extended to include the night-time and weekends when industrial and vehicle emissions are greatly reduced, pollution levels often are reported to be negligible. If urban polluters are allowed to average their emissions with those of rural areas, state levels often appear to create little risk. "Compliance" with federal standards judged by comparing legal limits with pollution averaged in this manner may have little relevance to the health of sensitive individuals.

Outdoors air quality is threatened most by two human activities: energy consumption and industrial emissions. Among thousands of individual chemicals, EPA regulates a number as "hazardous air pollutants", and only a few as primary pollutants. Many of these are emitted as exhaust from motor vehicles. People who spend long periods in transit are therefore likely to be more exposed to higher levels of pollution that surround transportation corridors. And pollution levels within vehicles are neither monitored nor regulated by the government.

The Public's Right-to-Know
The guiding principle behind government and corporate policies should be: The public has a right-to-know about health hazards in air, water, food, land and consumer product. To recognize hazards, the public must be better informed. This understanding is necessary for everyone to identify and avoid significant health threats. Democracy and effective participation in governmental affairs also require this knowledge; and without it, individual freedom is placed at risk.

The primary roadblocks to improvement of environmental quality are the absence of information and its protection by law as confidential and private property. Generating accurate evidence of amounts and locations of hazardous emissions, products and sites could be extremely useful if publicly accessible. An informed public would be better able to protect itself against dangerous exposures.

Some laws fail to demand full product labelling, necessary for consumers to recognize and avoid hazardous products in the marketplace. Other laws plainly protect knowledge of chemical ingredients as "confidential business information" (artificial flavours, inert ingredients in pesticides). Still other laws provide insufficient funding to monitor the quality of air, water, food and consumer products, or trends in illnesses plausibly linked to chemical hazards.

Secrecy is often legally protected. It may take many forms, including the failure to disclose hazardous situations to an unsuspecting public; failure to demand labelling of hazardous products, including ingredients; and failure to track production, distribution and fate of dangerous substances. Together these conditions result in continued exposure to hazardous chemicals - with neither our knowledge nor consent.

Several million tonnes of pesticides and "inert" ingredients are released to indoor and outdoor environments annually. Several thousand pesticide products are permitted to be released in homes and schools, and these releases may occur while children and others occupy buildings. Occupants are not normally notified of pesticide applications, or the health threats they impose.

Surveillance is crucial to the public's right-to-know about environmental hazards. The right-to-know is inhibited if governments do not track chemical production, release to the environment, and their use in products, disposal practices and human exposures.