Editing Arsenic (section)

==== San Pedro de Atacama ====
{{see also|Atacama people|Chinchorro mummies}}
[[File:Miscanti Lagoon near San Pedro de Atacama Chile Luca Galuzzi 2006.jpg|thumb|'''Miscanti Lagoon near San Pedro de Atacama Chile Luca Galuzzi 2006''']]
For several centuries, the people of [[San Pedro de Atacama]] in Chile have been drinking water that is contaminated with arsenic, and some evidence suggests they have developed some immunity.<ref>{{cite journal |last1=Goering |first1=P. |last2=Aposhian |first2=H.V. |last3=Mass |first3=M.J. |last4=Cebrián |first4=M. |last5=Beck |first5=B.D. |last6=Waalkes |first6=M.P. |title=The enigma of arsenic carcinogenesis: role of metabolism |journal=Toxicological Sciences |date=May 1999 |volume=49 |issue=1 |pages=5–14 |doi=10.1093/toxsci/49.1.5 |pmid=10367337 }}</ref><ref>{{cite journal |date=1996 |last1=Hopenhayn-Rich |first1=C. |last2=Biggs |first2=M. L. |last3=Smith |first3=Allan H. |last4=Kalman |first4=D. A. |last5=Moore |first5=Lee E. |title=Methylation study of a population environmentally exposed to arsenic in drinking water |journal=Environmental Health Perspectives |volume=104 |issue=6 |pages=620–628 |doi=10.1289/ehp.96104620 |pmid=8793350 |pmc=1469390 |bibcode=1996EnvHP.104..620H }}</ref><ref>{{cite journal |last1=Smith |first1=A.H. |last2=Arroyo |first2=A.P. |last3=Mazumder |first3=D.N. |last4=Kosnett |first4=M.J. |last5=Hernandez |first5=A L |last6=Beeris |first6=M. |last7=Smith |first7=M.M. |last8=Moore |first8=L.E. |display-authors=6 |title=Arsenic-induced skin lesions among Atacameño people in Northern Chile despite good nutrition and centuries of exposure. |journal=Environmental Health Perspectives |date=July 2000 |volume=108 |issue=7 |pages=617–620 |doi=10.1289/ehp.00108617 |pmid=10903614 |pmc=1638201 |bibcode=2000EnvHP.108..617S }}</ref> Genetic studies indicate that certain populations in this region have undergone natural selection for gene variants that enhance arsenic metabolism and detoxification. This adaptation is considered one of the few documented cases of human evolution in response to chronic environmental arsenic exposure.<ref>{{Cite journal |last1=Schlebusch |first1=Carina M. |last2=Gattepaille |first2=Lucie M. |last3=Engström |first3=Karin |last4=Vahter |first4=Marie |last5=Jakobsson |first5=Mattias |last6=Broberg |first6=Karin |date=2015-06-01 |title=Human Adaptation to Arsenic-Rich Environments |url=https://academic.oup.com/mbe/article/32/6/1544/1074042 |journal=Molecular Biology and Evolution |volume=32 |issue=6 |pages=1544–1555 |doi=10.1093/molbev/msv046 |pmid=25739736 |issn=0737-4038|doi-access=free }}</ref>