Children must be better protected from both new and existing chemicals that are known or possible toxins [49
]. To protect children from existing toxins, such as lead, mercury, and tobacco, the US EPA and FDA need more authority and resources to regulate and reduce emissions and exposures. Under our current system, efforts to enhance regulations to protect children from confirmed toxins are costly and protracted. Indeed, countless communities across the globe suffer from widespread environmental contamination. If there is any lesson from our experience with environmental toxins, it is that we need to identify environmental chemicals that are toxic before they are marketed or widely disseminated.
For new commercial chemicals, toxicity testing in animals should be required before they are marketed. For all new chemicals, including pesticides, extensive premarket testing should be required in multiple animal species of both sexes and at different developmental stages. These tests should be designed to have adequate statistical power to detect subtle differences within the ranges of exposure that occur in human populations. If implemented, these testing requirements would represent a dramatic departure from existing regulations, while providing a powerful incentive for industry to develop less toxic chemicals.
Toxicity testing in animals is essential but insufficient to protect pregnant women and children. For one thing, uncertainties about the safety of a chemical for humans will persist even after toxicity testing in animals is successfully completed. One additional safeguard that deserves further debate is whether prevalent environmental chemicals to which children could be exposed should undergo more extensive testing in human trials before they are marketed. If done, these trials should examine exposure, uptake (using biomarkers), and adverse effects among children or other populations only when the product is used as intended. For example, once animal toxicity testing of a residential pesticide is complete (including DNT and reproductive toxicity testing), a pesticide could undergo further testing in the home environment. Using an experimental group and a control group, researchers would compare levels of pesticides found in settled dust, on children's hands, and in their blood, urine, or hair. Children would be followed, when indicated, to ensure that an excess of neurobehavioral problems or other relevant outcomes did not develop among those whose homes were assigned to receive the pesticide application.
If such trials were undertaken, families would need to be fully informed about the purpose, potential benefits, and risks of participating. The trials should be conducted by the federal government—or other independent entities that do not have any ties to the chemical industry—and funded by an industry fee or tax. Community representatives would need to be involved in the review and approval of such trials, and ethical standards would need to be established regarding, for example, the role of data safety and monitoring boards. Many families would undoubtedly find it objectionable and would choose not to participate. Indeed, some products might never undergo testing if they failed to offer meaningful benefits to families, in which case the product would either be taken off the market or never reach the market.
This type of trial sounds extreme, but it is quite rational when compared to the existing approach of disseminating a potential toxin into children's environments without any human data about exposure, uptake, or toxicity. Furthermore, under our existing system, families are neither informed nor given an option to decline involvement in what ultimately are experiments exposing millions of pregnant women and children to potential toxins. Thus, we need to thoughtfully deliberate about whether these types of trials can be done in an ethical fashion. We also need to have further debate about whether it is ethical to continue to disseminate chemicals of unknown toxicity into children's environments or to allow children to continually be exposed to prevalent toxins, like lead, despite considerable evidence that they are toxic [82
]. Too often, it is left up to a few investigators or community leaders to discover and quantify the adverse effects of toxins, and advocate efforts to reduce children's exposure.