Exposure, chemical persistence

Maund SJ, Williams P, Whitfield M et al (2009) The influence of simulated immigration and chemical persistence on recovery of macroinvertebrates from cypermethrin and 3,4-dichloroaniline exposure in aquatic microcosms. Pest Manag Sci 65 678-687... 

In many cases, hazard based substitution eliminates the need for notoriously difficult exposure assessment. Persistence and bioaccumulation potential are surrogate measures of both hazard and exposure that can be applied quickly to all chemicals In order to identify those of greatest concern. 

The exposure pathway and physicochemical characteristics of a particular environmental chemical can provide useful information on the likelihood of childhood exposure (chapter 5). Age-specific exposure pathways of particular relevance include those during the prenatal and early developmental years postnatally (e.g. placental transfer, breast milk, toys, soil, indoor air/dust, child-care centres). Exposures to persistent environmental chemicals are of special concern, since the internal exposure may continue and result in a level sufficient to cause effects during critical developmental stages, even after the external exposure has ceased or been removed. 

Authorisation. The use of chemicals considered to be of very high concern would be subject to authorisation. The aim is for such chemicals to be phased out and substituted, unless industry can show that the use presents negligible risk or that it is acceptable, taking into account its socioeconomic benefits, the lack of safer chemicals and measures to minimise exposure. Chemicals of very high concern are likely to include carcinogens, mutagens or reprotoxic substances (CMRs), particularly persistent, bioaccumulative and toxic substances. 

Gramatica, Papa et al, 2004 Leip and Lammel, 2004 Pavan and Worth, 2008]. The longer a chemical persists, the higher the potential for human or environmental exposure to it. 

This book focuses on the chemical persistence and ocotoxicological behavior of pesticides In soil, water, and plants. Recent research data are presented on transport, adsorption and absorption, accumulation, degradation, biological effects, aquatic toxicity, air pollution, exposure, and risk estimation. 

Over the last few years, concerns have been raised abont the safety of several industrial chemicals in the environment and their impact on the health of hnmans and wildlife. Specifically, scientists are studying whether small amounts of APE-based chemicals in the environment are interfering with the endocrine systems of humans and wildlife. The central assumption to this hypothesis is that some industrial chemicals persist or bioaccumulate in the environment and therefore are available for direct or indirect contact with humans and wildlife. It was postulated that exposure to these compounds may be a risk or hazard to the health of humans and wildlife. 

Acute exposures involve a single exposure to the test chemical in order to determine if this is effective in producing immediate, delayed, or persistent... 

Exposure of wildlife to EDs also occurs via their food and in most ecosystems there is a tendency for persistent chemicals to bioaccumulate and biomagnify organisms higher up the food chain accumulate more of the chemical than those... 

Chronic Health Effect A chronic health effect is an adverse health effect resulting from long-term exposure to a substance. The effects could be a skin rash, bronchitis, cancer, or any other medical condition. An example would be liver cancer from inhaling low levels of benzene at your workplace over several years. The term is also applied to a persistent (months, years, or permanent) adverse health effect resulting from a short-term (acute) exposure. Chronic effects from long-term exposure to chemicals are fairly common. Recognize the PEL (permissible exposure level) for each substance in your workplace and minimize your exposure whenever possible. 

---