Premium
Total mercury and methylmercury concentrations over a gradient of contamination in earthworms living in rice paddy soil
Author(s) -
Abeysinghe Kasun S.,
Yang XiaoDong,
Goodale Eben,
Anderson Christopher W. N.,
Bishop Kevin,
Cao Axiang,
Feng Xinbin,
Liu Shengjie,
Mammides Christos,
Meng Bo,
Quan RuiChang,
Sun Jing,
Qiu Guangle
Publication year - 2017
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.3643
Subject(s) - methylmercury , mercury (programming language) , bioaccumulation , environmental chemistry , paddy field , earthworm , environmental science , contamination , ecosystem , soil contamination , terrestrial ecosystem , soil water , chemistry , agronomy , ecology , biology , soil science , computer science , programming language
Mercury (Hg) deposited from emissions or from local contamination, can have serious health effects on humans and wildlife. Traditionally, Hg has been seen as a threat to aquatic wildlife, because of its conversion in suboxic conditions into bioavailable methylmercury (MeHg), but it can also threaten contaminated terrestrial ecosystems. In Asia, rice paddies in particular may be sensitive ecosystems. Earthworms are soil‐dwelling organisms that have been used as indicators of Hg bioavailability; however, the MeHg concentrations they accumulate in rice paddy environments are not well known. Earthworm and soil samples were collected from rice paddies at progressive distances from abandoned mercury mines in Guizhou, China, and at control sites without a history of Hg mining. Total Hg (THg) and MeHg concentrations declined in soil and earthworms as distance increased from the mines, but the percentage of THg that was MeHg, and the bioaccumulation factors in earthworms, increased over this gradient. This escalation in methylation and the incursion of MeHg into earthworms may be influenced by more acidic soil conditions and higher organic content further from the mines. In areas where the source of Hg is deposition, especially in water‐logged and acidic rice paddy soil, earthworms may biomagnify MeHg more than was previously reported. It is emphasized that rice paddy environments affected by acidifying deposition may be widely dispersed throughout Asia. Environ Toxicol Chem 2017;36:1202–1210. © 2016 SETAC