Occurrence, speciation analysis and health risk assessment of arsenic in Chinese mitten crabs (Eriocheir sinensis) collected from China

Arsenic (As) is a major hazardous element in natural environments, and arsenic pollution is becoming an issue of concern worldwide. The more toxic inorganic arsenic, such as trivalent arsenite As(III) and pentavalent arsenate As(V), which normally can transform to organic arsenic compounds, such as arsenobetaine (AsB), arsenocholine (AsC), monomethyl arsenic acid (MMA), dimethyl arsenic acid (DMA), trimethyl arsenic acid (TMA), arsenosugars and arsenolipids. In this study, a total of 2130 individuals of Chinese mitten crabs were collected from seven locations and mixed to 71 samples. Total arsenic and six major species (AsC, AsB, DMA, MMA, As (III), and As (V)) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS), respectively. The target hazard quotient (THQ) was utilized to evaluate the human health risk. The total arsenic concentration and totals for the six arsenic forms are 0.25-1.66 mg/kg and 0.05-1.19 mg/kg wet mass, respectively. Except for HH and LH, the six arsenic species concentrations accounted for more than 50.0 % of the total arsenic. The less toxic AsB is the most predominant in crabs, comprising 50.0 %-90.0 % of the sum of six types of arsenic. The more toxic inorganic arsenic only range from 0.01 to 0.21 mg/kg wet mass, much less than the limit content of 0.50 mg/kg inorganic As in crustacea. The THQ values of inorganic arsenic through the consumption of Chinese mitten crabs are estimated, and the values are all less than 1, indicating that intaking Chinese mitten crabs collected from China will not cause an appreciable hazard risk to human health.