Editing Persistent organic pollutant (section)

== Health effects ==
{{See also|Health effects of pesticides}}
POP exposure may cause developmental defects, chronic illnesses, and death. Some are carcinogens per [[International Agency for Research on Cancer|IARC]], possibly including [[breast cancer]].<ref name="ritter"/> Many POPs are capable of [[endocrine disruption]] within the [[reproductive system]], the [[central nervous system]], or the [[immune system]].<ref>{{Cite journal |last1=Cheek |first1=A O |last2=Vonier |first2=P M |last3=Oberdörster |first3=E |last4=Burow |first4=B C |last5=McLachlan |first5=J A |date=1998-02-01 |title=Environmental signaling: a biological context for endocrine disruption. |journal=Environmental Health Perspectives |language=en |volume=106 |issue=suppl 1 |pages=5–10 |doi=10.1289/ehp.106-1533276 |issn=0091-6765 |pmc=1533276 |pmid=9539003|bibcode=1998EnvHP.106S...5C }}</ref> People and animals are exposed to POPs mostly through their diet, occupationally, or while growing in the womb.<ref name="ritter"/>  For humans not exposed to POPs through accidental or occupational means, over 90% of exposure comes from animal product foods due to bioaccumulation in fat tissues and bioaccumulate through the food chain. In general, POP serum levels increase with age and tend to be higher in females than males.<ref name="Vallack, H.W. 1998"/>

Studies have investigated the correlation between low level exposure of POPs and various diseases. In order to assess disease risk due to POPs in a particular location, government agencies may produce a [[human health risk assessment]] which takes into account the pollutants' [[bioavailability]] and their [[dose-response relationship]]s.<ref>{{cite book |vauthors=Szabo DT, Loccisano AE |title= Dioxins and Health: Including Other Persistent Organic Pollutants and Endocrine Disruptors|chapter=POPs and Human Health Risk Assessment |volume=3rd |pages=579–618|editor-last=Schecter |editor-first=A. |publisher=John Wiley & Sons |date=March 30, 2012| doi=10.1002/9781118184141.ch19 |isbn=9781118184141}}</ref>

=== Endocrine disruption ===
The majority of POPs are known to disrupt normal functioning of the endocrine system. Low level exposure to POPs during critical [[developmental biology|developmental]] periods of fetus, newborn and child can have a lasting effect throughout their lifespan. A 2002 study<ref name="Damstra, T. 2002">{{cite journal | author = Damstra T | year = 2002 | title = Potential Effects of Certain Persistent Organic Pollutants and Endocrine Disrupting Chemicals on Health of Children | journal = Clinical Toxicology | volume = 40 | issue = 4| pages = 457–465 | doi = 10.1081/clt-120006748 | pmid = 12216998 | s2cid = 23550634 }}</ref> summarizes data on endocrine disruption and health complications from exposure to POPs during critical developmental stages in an organism's lifespan. The study aimed to answer the question whether or not chronic, low level exposure to POPs can have a health impact on the endocrine system and development of organisms from different species. The study found that exposure of POPs during a critical developmental time frame can produce a permanent changes in the organisms path of development. Exposure of POPs during non-critical developmental time frames may not lead to detectable diseases and health complications later in their life. In wildlife, the critical development time frames are [[Uterus|in utero]], [[in ovo]], and during reproductive periods. In humans, the critical development timeframe is during [[prenatal development|fetal development]].<ref name="Damstra, T. 2002"/>

=== Reproductive system ===
The same study in 2002<ref name="Damstra, T. 2002"/> with evidence of a link from POPs to [[endocrine disruptor|endocrine disruption]] also linked low dose exposure of POPs to [[reproductive health]] effects. The study stated that POP exposure can lead to negative health effects especially in the [[human male reproductive system|male reproductive system]], such as decreased [[sperm]] quality and quantity, altered sex ratio and early [[puberty]] onset. For females exposed to POPs, altered [[human female reproductive system|reproductive tissues]] and [[pregnancy]] outcomes as well as [[endometriosis]] have been reported.<ref name="El-Shahawi, M.S. 2010"/>

====Gestational weight gain and newborn head circumference====
A Greek study from 2014 investigated the link between maternal weight gain during pregnancy, their [[polychlorinated biphenyl|PCB]]-exposure level and PCB level in their newborn infants, their [[birth weight]], [[Gestational age (obstetrics)|gestational age]], and head circumference. The lower the birth weight and head circumference of the infants was, the higher POP levels during [[prenatal development]] had been, but only if mothers had either excessive or inadequate weight gain during pregnancy. No correlation between POP exposure and gestational age was found.<ref>{{cite journal|last=Vafeiadi|first=M|author2=Vrijheid M |author3=Fthenou E |author4=Chalkiadaki G |author5=Rantakokko P |author6=Kiviranta H |author7=Kyrtopoulos SA |author8=Chatzi L |author9=Kogevinas M  |title=Persistent organic pollutants exposure during pregnancy, maternal gestational weight gain, and birth outcomes in the mother-child cohort in Crete, Greece (RHEA study)|journal=Environ. Int.|year=2014|volume=64|pages=116–123|doi=10.1016/j.envint.2013.12.015|pmid=24389008|doi-access=free|bibcode=2014EnInt..64..116V}}</ref>
A 2013 [[case-control study]] conducted 2009 in Indian mothers and their offspring showed prenatal exposure of two types of [[organochlorine pesticides]] ([[Hexachlorocyclohexane|HCH]], [[DDT]] and [[Dichlorodiphenyldichloroethylene|DDE]]) impaired the growth of the [[fetus]], reduced the birth weight, length, head circumference and chest circumference.<ref>{{cite journal|last=Dewan|first=Jain V|author2=Gupta P |author3=Banerjee BD. |title=Organochlorine pesticide residues in maternal blood, cord blood, placenta, and breastmilk and their relation to birth size|journal=Chemosphere|date=February 2013|volume=90|issue=5|pages=1704–1710|doi= 10.1016/j.chemosphere.2012.09.083|pmid=23141556|bibcode=2013Chmsp..90.1704D}}</ref><ref>{{cite journal | author = Damstra T | year = 2002 | title = Potential Effects of Certain Persistent Organic Pollutants and Endocrine Disrupting Chemicals on Health of Children | journal = Clinical Toxicology | volume = 40 | issue = 4| pages = 457–465 | pmid = 12216998 | doi = 10.1081/clt-120006748 | s2cid = 23550634 }}</ref>

=== Health effects of PFAS ===
{{See also|Regulation of chemicals#Issues}}
{{Excerpt|Per- and polyfluoroalkyl substances|Health and environmental effects|paragraphs=-1}}

=== Additive and synergistic effects ===
Evaluation of the effects of POPs on health is very challenging in the laboratory setting. For example, for organisms exposed to a mixture of POPs, the effects are assumed to be [[Additive effect|additive]].<ref name="Harrad, S. 2010">ed. Harrad, S., "Persistent Organic Pollutants" (2010).</ref> Mixtures of POPs can in principle produce [[Synergy#Toxicological synergy|synergistic effects]]. With synergistic effects, the toxicity of each compound is enhanced (or depressed) by the presence of other compounds in the mixture. When put together, the effects can far exceed the approximated additive effects of the POP compound mixture.<ref name="Walker, C.H. 2001"/>