The Reference Value for Biomonitoring in Chemicals Risk Area in Thailand

The workers’ biological standard value (WBSV) is generally used to assess chemicals health risks in community. It may cause the deviate biomonitoring. Therefore, this study was aimed to set the pilot reference value for exposed people to chemicals. The study was divided into three phases: the two phases for field-study method and one phase for stakeholder’s adoption. Phase I was proceeded in one industrial zone in Thailand during the years 2012-2014 to collect blood and urine samples of 402 working-age people in community accompanied with in-depth interview. The 4 heavy metals (arsenic, cadmium, lead, mercury) in blood and urine were analyzed by atomic absorption spectroscopy (AAS) analysis and inductively coupled plasma mass spectrometry (ICP-MS). The metabolites of 4 volatile organic compounds (VOCs, benzene, toluene, styrene, xylenes) in urine were analyzed by high performance liquid chromatography (HPLC) analysis. The 8 chemicals concentrations of the volunteers’ average chemicals concentration (VACC) were calculated. Phase II was proceeded during the years 2015-2016 to compare risk group identification between usage of VACC and usage of WBSV. The results were presented in mean value, standard deviation, percentage, and significant. The results showed approximately 90 percent of VACCs were lower than WBSV. The exceptional result was volunteers’ average urinary arsenic concentration. It was clearly higher than WBSV. The comparative results showed the adjusted amount of risk people by VACC was higher than the adjusted amount risk people by WBSV. Phase III was proceeded in the year 2017 for stakeholder’s adoption. This study indicated that general people’s average chemicals concentration should be used as the reference value for biomonitoring and active health surveillance.