Exposure to environmental contaminants

Human exposure to environmental contaminants has been investigated through the analysis of adipose tissue, breast milk, blood and the monitoring of faecal and urinary excretion levels. However, while levels of persistent contaminants in human milk, for example, are extensively monitored, very little is known about foetal exposure to xenobiotics because the concentrations of persistent compounds in blood and trans-placental transmission are less well studied. Also, more information is needed in general about the behaviour of endocrine disruptive compounds (and their metabolites) in vivo, for example the way they bind to blood plasma proteins. 

In 2002, the European Exposure Factors (ExpoFacts) database started as a 2-year project funded by CEFIC-LRI (European Chemical Industry Council, Long Range Research Initiative) to create a European database of factors affecting exposure to environmental contaminants. The aim was to create a public access data source, similar to the US-EPA Exposure Factors Handbook (US-EPA 1997), which has been widely used by European researchers, but with European data. Since 2006, the project is hosted by the European Commission s Joint Research Centre (JRC 2007). 

Biomonitoring data often provide an indication of human internal exposure to environmental contaminants, and this becomes the springboard... 

Children s exposure to environmental contaminants is a complex process that can occur as a result of release of pollutants from many sources that can reach the child through a number of different routes and pathways (Cohen Hubal et al., 2000b). Aggregate... 

Children s exposure to and dose from environmental contaminants are expected to be different from and, in many cases, much higher than those of adults. Both physiological and behavioural characteristics influence children s exposure to environmental contaminants. 

Much of the evidence for the adverse reproductive effects of selected toxicants will be based on cases involving wildlife exposures to environmental contaminants or on the experimental results of research exposing laboratory animals to large, pharmacological doses of potential toxicants. When available, data will be presented from accidental or intentional human and domestic animal exposures to toxicants associated with riot control and chemical warfare or with environmental catastrophes where incidences of infertility, abortion, and teratogenesis have been traced over the course of a number of years. 

Several stress responses to exposure to environmental contaminants have been studied and are exemplified by the SOS response (Quillardet et al., 1989 Sassanfar et al., 1990 Kenyon et al., 1998), the heat-shock response (Demple and Harrison, 1994 Lee et al., 2003), and the oxidative damage response (Hidalgo et al., 1994 Asad et al.,... 

Another panelist thought Section 2.5 (page 224) does not adequately distinguish the implications of transplacental and breast milk exposure. This panelist thought the profile should emphasize that transplacental transfer occurs at the earliest stage of life, when humans are particularly prone and susceptible to the potential effects of exposure to environmental contaminants, while breast milk exposure occurs slightly later in life and does not appear to be associated with adverse developmental effects. 

The determination of the potential risk associated with chemical use and dermal exposure to environmental contaminants is often based on an evaluation of in vivo and in vitro dermal absorption in the rat together with in vitro evaluation using... 

Misuse of various chemicals including industrial pesticides, toxic substances, and chemical warfare agents (CWAs) requires adequate personal protective equipment and immediate skin decontamination [151]. Since the time of World War 11, scientists have made a concerted effort to improve prophylactic and therapeutic interventions to counteract cutaneous exposure to CWAs [147]. To curtail dermal systemic exposure to environmental contaminants, most material safety data sheets (MSDSs) recommend either water rinsing or soap-and-water decontamination to remove chemicals from the skin surface [152, 153]. However, it is vital that the skin be washed in such a way that does not elicit the wash-in (W-I) effect [154], The W-1 effect is defined as an enhancement of percutaneous absorption elicited specifically by skin decontamination, particularly with water. It simply means that as some chemical contaminants are washed off the skin, the chemical substance may also wash into the skin and thus become more systemically bioavailable. 

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