Spray irrigation of landfill leachate: estimating potential exposures to workers and bystanders using a modified air box model and generalised source term.
Generalised source term data from UK leachates and a probabilistic exposure model (BPRISC(4)) were used to evaluate key routes of exposure from chemicals of concern during the spraying irrigation of landfill leachate. Risk estimates secured using a modified air box model are reported for a hypothetical worker exposed to selected chemicals within a generalised conceptual exposure model of spray irrigation. Consistent with pesticide spray exposure studies, the key risk driver is dermal exposure to the more toxic components of leachate. Changes in spray droplet diameter (0.02-0.2 cm) and in spray flow rate (50-1000 l/min) have little influence on dermal exposure, although the lesser routes of aerosol ingestion and inhalation are markedly affected. The risk estimates modelled using this conservative worst case exposure scenario are not of sufficient magnitude to warrant major concerns about chemical risks to workers or bystanders from this practice in the general sense. However, the modelling made use of generic concentration data for only a limited number of potential landfill leachate contaminants, such that individual practices may require assessment on the basis of their own merits.
Gray
Duncan
D
Integrated Waste Management Centre, Cranfield University, Cranfield MK43 0AL, UK.
Pollard
Simon J T
SJ
Spence
Lynn
L
Smith
Richard
R
Gronow
Jan R
JR
D000336:Aerosols / Q000633:toxicity; D000393:Air Pollutants / Q000633:toxicity*; D016477:Artifacts; D004781:Environmental Exposure / Q000009:adverse effects*; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D008962:Models, Theoretical; D009010:Monte Carlo Method; D016273:Occupational Exposure / Q000009:adverse effects; D012037:Refuse Disposal / Q000379:methods*; D018570:Risk Assessment / Q000379:methods; D012867:Skin / Q000187:drug effects; D006113:United Kingdom
D000336:Aerosols; D000393:Air Pollutants