Biomonitoring of Uruguayan workers exposed to arsenic from chromated copper arsenate (CCA) used in wood impregnation process

BACKGROUND AND AIM: In Uruguay there are 20 wood-impregnation plants which mostly use chromated copper arsenate (CCA) as preservative. This study aims to show the results of our CCA-woodworkers’ Arsenic exposure biomonitoring for over seven years. In CCA plants, the wood is impregnated into a pressure cylinder performing different cycles of vacuum-pressure-vacuum. Exposure to arsenic in woodworkers may occur through inhalation, dermal exposure, and ingestion during working hours. Owing to the difficulty of replacing CCA for economic reasons, Uruguayan authorities promote the use of GMP that consider recommendations of international occupational safety organizations to minimize negative impacts on the environment and workers’ health. In this regard, the “Guidelines on good practices in wood impregnation” were published in 2007 which establish safety and prevention measures including the use of personal protection equipment. As Uruguay adopted the American Conference of Governmental Industrial Hygienists (ACGIH) recommendations, urine samples of exposed workers must be collected twice a year, for urinary inorganic arsenic plus metabolites analysis (As-U). The recommended biological limits values (BLV) provided by ACGIH for As-U should be below to 35 μgL−1 METHODS: We present and discuss the working conditions and results of As-U from 2014 to 2020, in 479 urine samples from workers of six CCA impregnation plants that were analyzed in our lab by Hydride Generation Atomic Absorption Spectrometry. RESULTS:The As-U results were below BLV in 96,5% of samples. Only 17 samples were higher and after a minimum period of 15 days of workplace removal as requested by guidelines, the workers re-established safe As-U values. CONCLUSIONS:As shown, results indicate low occupational exposure risks to arsenic and reveal the importance of the correct use of personal protective equipment and the relevance of having national guidelines for these practices. Besides the biological control, it is necessary to identify possible causes and carry out the appropriate corrective actions. KEYWORDS: arsenic, chromated copper arsenate (CCA), biomonitoring arsenic