Arsenic Exposure Assessment for Children Playing on CCA-Treated Playground Structures. C. Campbell, C. Norman, J. Worgan, B. Curwin, M. Mitchell, and J. Lin, PMRA, Health Canada, Sir Charles Tupper Building, 2250 Riverside Drive, Ottawa, Ont, Canada, K1A 0K9
As part of an official re-evaluation of heavy duty wood preservatives, the Pest Management Regulatory Agency has performed a probabilistic exposure assessment on arsenic for children playing on chromated copper arsenate (CCA)-treated playground structures. Inorganic arsenic was identified as the component of primary concern in the formulation due to its carcinogenic properties. The routes of exposure examined in assessment included: dermal contact with dislodgeable residues on structures, ingestion of dislodgeable residues due to hand-to-mouth contact, ingestion of arsenic in soil surrounding structure and dermal contact with arsenic in soil surrounding structures. The exposure scenario included two age groups (2-5 and 6-10 years) and three seasons (summer, spring/fall, winter). Many of the distributions describing the variables were based on previously published data. These variables include: arsenic in dislodgeable residues, arsenic in soil, children’s body weights, children’s body surface area, soil ingestion rates, soil adherence to skin and dermal absorption of arsenic. Some variables, however, were not well quantified; these included: activity specific transfer coefficient for children playing on pressure treated wood, time spent in contact with playground structures as well as hand-to-mouth transfer factors. A sensitivity analysis was performed to identify the primary exposure variables; these included: dislodgeable residues, transfer coefficient, time in contact with playground structure and dermal absorption. The majority of the exposure estimate assessment included: dermal contact with dislodgeable residues on structures, ingestion of dislodgeable residues due to hand-to-mouth contact, ingestion of arsenic in soil surrounding structure and dermal contact with arsenic in soil surrounding structures. The exposure scenario included two age groups (2-5 and 6-10 years) and three seasons (summer, spring/fall, winter). Many of the distributions describing the variables . . . . . . [RiskWorld Note: Submitted abstract incomplete]