title: Dioxin-like compounds in Australian sewage sludge--review and national survey.
abstract: An Australian survey of dioxin-like compounds in sewage sludge was conducted in two parts (a) a national survey, and (b) a time-study. All sewage sludge samples analysed as part of these studies had low overall concentrations of dioxin-like compounds. Out of 37 samples, all except one, were within the reported concentration range of soil within the Australian environment. The mean concentration of dioxin-like compounds in the Australian sewage sludge survey of 2006 was found to be 5.6 (s.d. 4.5) ng WHO(05) TEQkg(-1) (n=14) and were within the range of 1.2-15.3 ng WHO(05) TEQ kg(-1). All the Australian sewage sludge samples cited in these studies were below the Victorian EPA "investigation limit" of 50 ng WHO(98) TEQ kg(-1), and well below the European proposed guidelines of 100 ng I-TEQ kg(-1). The burden of dioxin-like compounds in Australian sewage sludge is low and its land application as biosolids is not likely to pose a problem. A general positive relationship was found between population of the town producing the waste and both dioxin-like PCDD/Fs and dioxin-like PCBs. The one exception to this trend was sludge from a town that had a history of smelting and had a relatively high burden of dioxin-like compounds. Sludge from one rural WWTP also had a higher burden of dioxin-like compounds. The treatment plant services a geographically isolated town with a low population and no known emitters of dioxin-like compounds. However, this sample also had a relatively high burden of dioxin-like PCBs, which could be the source of the dioxin-like PCDD/Fs found in this sludge. The time study analyzing sludges from three WWTP from the same city between the years 2002 and 2006 found no apparent difference between WWTPs, but a statistically significant decline of 1.49 ng WHO(05) TEQ kg(-1) per year. Also, a comprehensive review of the scientific literature, presents typical levels and sources of dioxin-like compounds in international sewage sludges.
authors.affiliation: School of Applied Sciences (Bld 3 Level 1), RMIT University, Melbourne, Victoria, Australia. bradley.clarke@student.rmit.edu.au
authors.forename: Bradley
authors.initials: B
authors.lastname: Clarke
authors.forename: Nichola
authors.initials: N
authors.lastname: Porter
authors.forename: Robert
authors.initials: R
authors.lastname: Symons
authors.forename: Judy
authors.initials: J
authors.lastname: Blackbeard
authors.forename: Peter
authors.initials: P
authors.lastname: Ades
authors.forename: Philip
authors.initials: P
authors.lastname: Marriott
mesh_terms: D001315:Australia; D003625:Data Collection / Q000379:methods; D004147:Dioxins / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D012196:Review Literature as Topic; D012722:Sewage / Q000737:chemistry*
chemical_list: D004147:Dioxins; D004785:Environmental Pollutants; D012722:Sewage