Notable case, Dengjiatang (Chenzhou), Hunan, China
Dengjiatang, Chenzhou (arsenic)
郴州市邓家塘
A farming area in southern Hunan poisoned in 1999 by the waste of an arsenic products factory. Here in 2001 Chen Tongbin's group set up what is described as the world's first demonstration base for phytoremediation of arsenic-contaminated soil, using the fern Pteris vittata.
At a glance
- Status
- Remediation under way
- Area
- 50 ha on land1
- Activity
- until 1999
- Media
- soil, surface water, living organisms
- Kind of site
- chemical works, illegal dumping
- Area. About 50 hectares of farmland abandoned after the 1999 incident (Li and colleagues, 2025).
- People affected. "Hundreds" of residents poisoned according to Li and colleagues (2025); no exact figure in the sources read.
Contaminants
Metalloids
Status
Remediation under way
Phytoremediation with Pteris vittata ran continuously from 2002 to 2008. A 2021–2023 study still distinguishes contaminated, remediated and control soils on the spot; the present state of the whole abandoned area was not checked for this record.
Story
In 1999 a company making arsenic compounds at Dengjiatang, in the Chenzhou area, dumped its residues in the natural hollows around the factory. Arsenic contaminated the surrounding water, soil and crops: hundreds of residents were poisoned and about 50 hectares of farmland were abandoned.
In 2001 the group of Chen Tongbin, at the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, which had identified Pteris vittata as a plant able to hyperaccumulate arsenic, chose the site for a field demonstration base for phytoextraction. In April 2002, after ploughing, the ferns were planted and then mown every year until 2008.
The site has remained a place of study: research by Xiangnan University compared contaminated soil, soil under the fern and control soil there between 2021 and 2023.
Timeline
- 1999Residues from an arsenic products factory contaminate water, soil and crops; hundreds are poisoned.
- 2001Chen Tongbin's group sets up the phytoremediation demonstration base.
- 2002April: Pteris vittata is planted.
- 2008End of the six years of continuous phytoextraction.
- 2025Publication of the study on recovery of bacterial communities in the remediated soil.
Health
The 1999 incident caused arsenic poisoning in hundreds of residents (Li and colleagues, 2025, without an exact figure).
Plants and fungi at this site
PhytoremediationField scale, 2002–2008
Pteris vittata
Field phytoextraction led by Chen Tongbin (Chinese Academy of Sciences). After ploughing the contaminated soil, in April 2002 the fern Pteris vittata was planted at 40 × 40 cm spacing; the fronds, which accumulate the arsenic, were mown and removed once a year. Treatment went on without a break for six years.
Outcome The Chen group's original data on the fall in soil arsenic were not read for this record (the Springer chapters could not be opened) and remain to be added. The study by Li and colleagues (2025) on soils from the site finds, in those remediated with the fern, more available nutrients, greater bacterial diversity and more complex microbial networks than in contaminated soil, that is, a partial recovery of soil functions.
- Li F., Liu J., Tian T., Deng B., Xiao H. The Remediation of Arsenic-Contaminated Soil by Pteris vittata L. Facilitates the Recovery of Soil Bacterial Diversity and Network Complexity. Microorganisms 13(10): 2316, 2025
- Chen T.-B. et al. Phytoremediation of Arsenic-Contaminated Soil in China. In: Phytoremediation, Methods in Biotechnology 23 (pointer, not read: access blocked), 2007
From the literature
Species that acted on one of this site's contaminants in at least one study. The list is automatic and takes no account of this site's soil, concentrations or climate.
Plants
- Pteris vittataChinese brake fernEvidence: field
- Arundo donaxGiant reedEvidence: greenhouse
- Azolla carolinianaCarolina mosquito fernEvidence: laboratory
- Lemna minorCommon duckweedEvidence: laboratory
Fungi
- Funneliformis mosseaeEvidence: greenhouse
- Aspergillus nigerBlack mouldEvidence: laboratory
- Fomitopsis pinicolaRed-belted conkEvidence: laboratory
- Mucor circinelloidesEvidence: laboratory
Nearby
Sources
Draft compiled from public sources, not yet reviewed.