Total arsenic and speciation analysis of saliva and urine samples from individuals living in a chronic arsenicosis area in China Original paper

What was studied?

The study aimed to assess arsenic exposure in individuals from an arsenic-contaminated area in Shanyin County, Shanxi Province, China. Researchers focused on measuring total arsenic and its species in both urine and saliva samples to investigate the potential use of saliva as a biomarker for arsenic exposure. They compared arsenic concentrations in these biological fluids, correlating them with arsenic levels in drinking water and the presence of skin lesions. The study also explored the relationship between arsenic metabolism and species found in both urine and saliva.

Who was studied?

The participants in the study included 70 individuals from 42 families residing in Shanyin County, an area with a high prevalence of arsenicosis, a disease caused by chronic arsenic exposure. The subjects were mostly adults, with the study including both male and female participants, with ages ranging from 21 to 78 years. This population was selected due to their exposure to arsenic-contaminated drinking water, with some individuals also exhibiting skin lesions commonly associated with arsenic poisoning.

Most important findings

The study found that both salivary and urinary arsenic levels were positively correlated with the arsenic concentration in drinking water, as well as with the presence of skin lesions. Specifically, as the arsenic concentration in drinking water increased, so did the levels of arsenic in both saliva and urine, confirming that these biological fluids can serve as useful indicators of arsenic exposure. The research also revealed that while saliva exhibited a lower concentration of arsenic compared to urine, there was a strong correlation between the arsenic found in saliva and that in urine, making saliva a potential biomarker for total arsenic exposure. However, it was noted that arsenic in saliva did not show the same degree of methylation as in urine, with inorganic arsenic being the most prevalent species in saliva. In contrast, urine predominantly contained methylated species like dimethylarsinate (DMA) and methylarsonic acid (MMA).

Key implications

The findings suggest that saliva can be used as a non-invasive, practical biomarker for assessing total arsenic exposure, particularly in population studies. However, while saliva can help monitor exposure levels, it is less effective in evaluating arsenic metabolism, which can be better assessed through urine samples. This distinction underscores the importance of selecting appropriate biomarkers depending on the type of arsenic exposure and the desired analysis. The study also emphasizes the need for continued exploration into the relationship between arsenic species and human health, particularly in understanding the biological mechanisms underlying arsenic toxicity and its systemic effects.