Emerging chemicals, human health impact

A Revision of Current Models for Environmental and Human Health Impact and Risk Assessment for Application to Emerging Chemicals... 

The characteristics of the applied models have been described in detail in the chapters Environmental Fate Models [50] and A Revision of Current Models for Environmental and Human Health Impact and Risk Assessment for Application to Emerging Chemicals [49] and only a brief overview is given here. Since each model has its own approach (i.e., QWASI is focused on the aquatic system), the combined results are expected to give a wider view with in-depth analyses for different aspects compared to just one model with its special characteristics. 

Emerging chemical regulation, such as REACH, is focusing on the need for characterizing all chemical substances in use in terms of their environmental and human health impacts. This basic tenet of no data—no market will set the trend for regulations to be implemented in other parts of the world. The development of such information should allow sound, science-based decisions to be made about chemicals, their use, and, where necessary, substitution strategies. For the producers and down stream users of chemicals, there will be new opportunities for innovation, but within a more stable business environment than we have had in the recent past. This has to be positive for flame-retardants as well as for other chemicals. 

At the same time, however, there is emerging evidence that PMN requirements have significantly inhibited innovation in the chemical industry. Section 5 has inevitably had some impact on innovation, and EPA regulations that add to the basic statutory requirements are likely to impose burdens on the chemical industry that are unnecessary. That is why CMA recommends that the Agency, at a minimum, limit those regulations to the clear requirements of the statute. Requirements such as supplemental reporting of PMN information, mandatory consumer contacts, advance substantiation of confidentiality claims, and the "invalidation" of incomplete PMNs, will only serve to increase the costs of a process that already imposes substantial burdens. Since EPA can adequately protect human health and the environment without these requirements, they should be eliminated. 

There is an emerging body of evidence that suggests person-to-person differences in exposure play an important role in the variability and uncertainty associated with risk assessments for chemicals (and other agents). The traditional or standard default approaches used in human health risk assessment often do not effectively evaluate interindividual variation and may underestimate the impact of chemical exposures on particular groups of individuals. Traditional approaches must be refined to adequately account for temporal variation in factors that contribute to complex aggregate exposure patterns (e.g., chemical-specific exposure media concentrations and time-activity interactions by humans) involving multiple, intermittent exposures. 

Within emergency medicine, it is a common perception that chemical incidents are rare events. It has often been quoted in the past that there are approximately 1000 acute chemical incidents per year in England and Wales that may impact human health and that the majority of these events involve less than four casualties. For the purposes of public health, a chemical incident is defined as an event in which there is, or could be, exposure of the public to chemical substances that cause, or have the potential to cause, ill health . Hospital staff and emergency services personnel are considered to be members of the public in this definition. In 2005, the UK Health Protection Agency recorded more than 1000 chemical incidents, and it was estimated that approximately 27,000 people may have been exposed, of whom about 3000 reported with symptoms. It is thought that the actoal numbers may be considerably higher. 

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