Citation:
Duncan Gray, Simon J.T. Pollard, Lynn Spence, Richard Smith and Jan R. Gronow, Spray irrigation of landfill leachate: estimating potential exposures to workers and bystanders using a modified air box model and generalised source term. Environmental Pollution, Feb 2005, Vol.133(3), pp.587-599
Abstract:
Generalised source term data from UK leachates and a probabilistic exposure
model (BPRISC4) 12 were used to evaluate key routes of exposure from chemicals
of concern during the spraying 13 irrigation of landfill leachate. Risk
estimates secured using a modified air box model are reported 14 for a
hypothetical worker exposed to selected chemicals within a generalised
conceptual exposure 15 model of spray irrigation. Consistent with pesticide
spray exposure studies, the key risk driver is 16 dermal exposure to the more
toxic components of leachate. Changes in spray droplet diameter 17 (0.02-0.2 cm)
and to spray flow rate (50-1000 l/min) have little influence on dermal exposure,
18 although the lesser routes of aerosol ingestion and inhalation are markedly
affected. The risk 19 estimates modelled using this conservative worst case
exposure scenario are not of sufficient 20 magnitude to warrant major concerns
about chemical risks to workers or bystanders from this 21 practice in the
general sense. However, the modelling made use of generic concentration data for
22 only a limited number of potential landfill leachate contaminants, such that
individual practices 23 may require assessment on the basis of their own merits.