The survey of probable cases of diseases caused by arsenic in some wood factory in Phrapradaeng district, Samutprakarn province, January 2021

Abstract

Four out of five wood factory workers who had been exposed to unknown wood preservative had an excess inorganic arsenic exposure. This study aims to determine epidemiologic characteristics of probable cases of diseases caused by arsenic in a wood factory and identify whether it was work related, and recommend preventive and control measure. This cross-sectional descriptive study conducted in January 2021 started by diagnosis verification of the four index cases. The active case finding was then conducted by collecting demographic information and interviewing by using the disease investigation form for arsenic- related diseases. Additionally, clinical study was also performed for diagnosis of the diseases caused by arsenic by history taking, physical examination, and laboratory analysis. An environmental investigation was conducted by workplace survey and collecting the workplace environmental samples. This study found that all four index cases are diagnosed as probable cases of diseases caused by arsenic, leading to further investigation which resulted in the detection of more cases involved. Attack rate of probable cases of diseases caused by arsenic in this factory is 93.33%. The vast majority of the cases is male (90%), an average age is 34.27 years, a nationality is mainly the Burmese (63.34%), and an average work experience is 5.53 years. All of them worked in a wooden wheel warehouse and were mostly in the wheel assembly department. The vast majority of them denied having arsenic exposure from the environments outside their work. None of them have had abnormal symptoms. There are no physical examination results/laboratory results specifically consistent with the diseases caused by arsenic. The average urine inorganic arsenic level is 114.69 Ug As/L. Based on the workplace survey, the wood preservative containing arsenic named chromated copper arsenate (CCA) was found in their work processes. An excess level of arsenic was found in all eight environmental surface samples. In conclusion, a large number of probable cases of diseases caused by arsenic were identified in a wood factory. However, they were not diagnosed as confirmed cases due to lack of symptoms specifically consistent with the diseases caused by arsenic. The cause of this outbreak is probably related to work. Therefore, the implementation of appropriate control measures and further follow-up on long-term health effects are needed.