Endocrine Disruptors

5. What are potential sources of EDC exposure?

The source document for this Digest states:

Often the weakest link in determining whether observed adverse effects in humans and/or wildlife are linked to EDCs is the absence of adequate exposure data. Often data are limited to accidentally highly exposed groups. Most exposure information has focused on the presence of persistent organic pollutants in Europe and North America. Data on the magnitude and trends of global human or wildlife exposure are limited. Potential sources of exposure are through contaminated food, contaminated groundwater, combustion sources, and contaminants in consumer products. Information on exposure during critical development periods is generally lacking. The exposure data sets that exist are primarily for various environmental media (air, food, water) rather than the most relevant internal exposure (blood, tissue). Limited exceptions are human breast milk and adipose tissue samples. Worldwide, despite large expenditures of money, time, and effort, comparable data sets for assessing exposures to EDCs for humans or wildlife are not available. Such information is essential to adequately evaluate exposure–response relationships in field and epidemiological studies and to use these relationships to produce credible risk assessments.

Source & ©: IPCS"Global Assessment of the state-of-the-science of Endocrine disruptors "
 Executive Summary (Chapter 1) page 3 section 1.6

General exposure:

For details on:	See IPCS assessment:
Exposure issues for EDCs	Chapter 2, section 2.5, page 8
The kind of exposure studies that are needed on EDCs	Chapter 6, section 6.1, page 89

Sources and pathways:

For details on:	See IPCS assessment:
Sources of exposure to EDCs	Chapter 6, section 6.2.1, page 90
Pathways of exposure to EDCs via air, water, soil, sediment, food and consumer products	Chapter 6, section 6.2.2, page 91
Exposure via air to volatile compounds such as lindane, nonhalogenated aromatic hydrocarbons, phenols and phthalate esters	Chapter 6, section 6.2.2.1, page 91
Exposure via water to water-soluble compounds such as pesticides, industrial chemicals and natural hormones	Chapter 6, section 6.2.2.2, page 91
Exposure via soil and sewage sludge to compounds such as PCBs, dioxins and PBDEs	Chapter 6, section 6.2.2.3, page 91
Exposure of wildlife via sediments	Chapter 6, section 6.2.2.4, page 91
Exposure via food, the major exposure route for humans and wildlife	Chapter 6, section 6.2.2.5, page 91
Exposure via consumer products such as exposure to phthalate esters in young children chewing on toys and teething rings	Chapter 6, section 6.2.2.6, page 92

Intake and uptake:

For details on:	See IPCS assessment:
The difference between intake and uptake of environmental chemicals with EDC potential	Chapter 6, section 6.2.3, page 92
The internal dose and pharmacokinetics of EDCs	Chapter 6, section 6.2.4, page 92

Wildlife exposures:

For details on:	See IPCS assessment:
Exposure to persistent organic pollutants in the Baltic sea, Great Lakes region and Arctic region	Chapter 6, section 6.3.1.1, page 93
Global distribution of DDT and PCBs in marine mammals	Chapter 6, section 6.3.1.1.4, page 95
The impact of TBT, used in antifouling paints applied to hulls of ships, on coastal areas	Chapter 6, section 6.3.1.2, page 96
The source and fate of alkyl phenols (APs), alkylphenol ethoxylates (APEs) and their degradation products	Chapter 6, section 6.3.1.3, page 96
Summary and conclusions on wildlife EDC exposures	Chapter 6, section 6.3.1.4, page 98

Human exposures:

For details on:	See IPCS assessment:
Dioxins ingested through food and decreasing levels in breast milk	Chapter 6, section 6.3.2.1, page 98
PCB exposure due persistence in the environment and continued use in some parts of the world	Chapter 6, section 6.3.2.3, page 100
PBDEs that are present in food and may be released from television sets and computers, and are found in increasing amounts in human breast milk	Chapter 6, section 6.3.2.3, page 100
DDT that is still used in some developing countries	Chapter 6, section 6.3.2.4, page 100
Phthalates that are present in various types of plastics	Chapter 6, section 6.3.2.5, page 100
Atrazine that may be present in groundwater and drinking water	Chapter 6, section 6.3.2.6, page 100
Phytoestrogens that are naturally present in foods such as soy	Chapter 6, section 6.3.2.7, page 100
Conclusions on human EDC exposures	Chapter 6, section 6.3.2.8, page 101

Measurement:

For details on:	See IPCS assessment:
Ways of measuring EDC exposure	Chapter 6, section 6.4, page 101
Key issues involved in sampling to measure EDC exposure	Chapter 6, section 6.4.1, page 102
Multi-residue methods that can test for a broad range of chemicals in a single sample used for screening purposes	Chapter 6, section 6.4.2.1, page 102
Using combined chemical and biological methods to identify EDCs in environmental samples	Chapter 6, section 6.4.2.2, page 102
Biological methods currently available for detecting hormonally active substances	Chapter 6, section 6.4.2.2.1, page 102
The toxic identification evaluation (TIE) approach that uses in vitro bioassays in conjunction with chemical methods for identifying EDCs	Chapter 6, section 6.4.2.2.2, page 103

Mixtures, QA/QC, exposure models & SARs:

For details on:	See IPCS assessment:
Potential endocrine disruptors that exist as mixtures of related chemicals (isomers and congeners)	Chapter 6, section 6.4.3, page 103
PCB congeners and other EDCs that exist as mirror images (chiral pairs)	Chapter 6, section 6.4.3.1, page 103.
The various systems for weighting the amounts of individual congeners in a mixture in proportion to their toxicity	Chapter 6, section 6.4.3.2, page 103
The importance of quality assurance and quality control (QA/QC) procedures to ensure EDC measurements from around the world are comparable	Chapter 6, section 6.4.4, page 104
Exposure models that can be used when measurements are limited	Chapter 6, section 6.4.4, page 104
Structure-activity methods that can be used to estimate the potential EDC activity of untested chemicals	Chapter 6, section 6.4.5, page 104
Summary and conclusions on EDC exposure issues in wildlife and humans	Chapter 6, section 6.5, page 105