[Show abstract][Hide abstract] ABSTRACT: This study reports a survey of occupational exposure to copper chrome arsenic (CCA) based wood preservatives during vacuum pressure timber impregnation. The survey involved biological monitoring based on analysis of chromium and arsenic in urine samples collected from UK workers. The aim of the study was to determine the extent of occupational exposure to arsenic and chromium in the UK timber treatment industry. The objectives were to collect and analyse urine samples from as many workers as possible, where CCA wood preservatives might be used, at 6 monthly intervals for 2 years. In addition, to investigate day-to-day variations in urinary excretion of chrome and arsenic by collecting and analysing three samples a week for 3 weeks in subsets of workers and controls (people not occupationally exposed). All urine samples were analysed for chromium and inorganic arsenic. To investigate any residual interference every sample was accompanied by a short questionnaire about recent consumption of seafood and smoking. The analytical methods for arsenic used a hydride generation technique to reduce interference from dietary sources of arsenic and also a technique that would measure total arsenic concentration in urine. The main findings show that workers exposed to CCA wood preservatives have concentrations of inorganic arsenic and chromium in urine that are significantly higher than those from non-occupationally exposed people but below biological monitoring guidance values that would indicate inhalation exposure at UK occupational exposure limits for chromium and arsenic. The effects of consumption of seafood on urinary arsenic were not significant using the hydride generation method for inorganic arsenic but were significant if 'total' arsenic was measured. The 'total' arsenic method could not distinguish CCA workers from controls and is clearly unsuitable for assessment of occupational exposure to arsenic. There was a significant increase in the urinary concentration of chromium in workers over the four sample collection rounds indicating increasing exposure to chromium during the 2 years of the study. This unexpected finding may be worth further investigation. Overall, the study demonstrated the utility of biological monitoring for assessment of occupational exposure to chromium and arsenic.
Full-text · Article · Aug 2006 · Annals of Occupational Hygiene
[Show abstract][Hide abstract] ABSTRACT: The effect of internal glove contamination was investigated using N-methyl pyrrolidone (NMP) as a biological marker to assess systemic absorption when wearing internally contaminated gloves, and when not wearing gloves but subjected to the same challenge contaminant. The routes by which the insides of gloves become contaminated were also investigated. The area of dermal contamination was quantified using a fluorescent tracer dye and a surface monitoring fluorimeter. The main routes of internal glove contamination were found to be self-contamination, cuff entry and failed gloves. Wearing internally contaminated gloves led to higher systemic absorption than was gained from the equivalent skin contamination when not wearing gloves. Repeat wetting of fingers with aqueous NMP, when gloves were not worn, gave higher systemic absorption than the equivalent continuous exposure, probably due to the low volatility of NMP leading to increased concentration and longer residence time on the skin.