M. Mortimer

Occurrence and implications of estrogens and xenoestrogens in sewage effluents and receiving waters from South East Queensland.

We report a survey on the occurrence of estrogens (estrone, E1; 17beta-estradiol, E2; 17alpha-ethynylestradiol, EE2) and xenoestrogens (bisphenol-A, BPA; 4-t-octylphenol, 4-t-OP; 4-nonylphenols, 4-NP; and nonylphenol mono- and di-ethoxylates, NPE1 and NPE2) in effluents from five wastewater treatment plants and their receiving waters in South East Queensland. The total xenoestrogen concentrations in effluent ranged between 2446 ng/L and 6579 ng/L, with 4-NP and NPE1-2 having much higher concentration levels than BPA and 4-t-OP. The estrogen levels in effluent varied from 9.12 to 32.22 ng/L for E1, from 1.37 ng/L to 6.35 ng/L for E2 and from 0.11 ng/L to 1.20 ng/L for EE2. No significant differences (p<0.05) in the concentrations of the selected estrogenic compounds were found for the effluents from the five sewage treatment plants. The estrogens and xenoestrogens were also found in the receiving waters at relatively lower concentration levels due to dilution of effluents in the rivers. Based on the chemical analysis data and relative potency of the compound from in vitro and in vivo bioassays from the literature, the calculated in vitro EEQ values (estrogen equivalents) in the receiving river waters downstream of the effluent discharge points ranged from 1.32 to 11.79 ng/L, while the in vivo EEQ values (vitellogenin response in rainbow trout) ranged from 2.48 to 21.18 ng/L. The three estrogens accounted for the majority of the EEQ in the water samples. This study indicates that the rivers of South East Queensland are at potential risk.

Persistent Lipophilic Contaminants and Other Chemical Residues in the Southern Hemisphere

Data on the levels of persistent lipophilic contaminants and other chemicals have been reviewed and the dominant persistent lipophilic contaminants in the Southern Hemisphere found to be the chlorohydrocarbons commonly described as the DDTs, HCHs, and the PCBs. The distribution patterns suggest that long-range transport, probably by global distillation, occurred with these substances. Endosulfan residues appear significant in areas of usage but the data are limited. The data are in accord with a reduction in usage of chlorohydrocarbons in developed countries, but an increase in usage in many tropical countries. A systematic comparison of data on the northern and southern hemispheres indicates that the northern hemisphere is generally more contaminated than the southern hemisphere. It also suggests that the process of equilibration between the two hemispheres is relatively slow. In addition, with the HCBs there is an equatorial to polar gradation in concentration probably as a result of global distillation...

Pesticide and trace metal concentrations in Queensland Estuarine Crabs

Trace metals, metalloids and pesticide content were quantified in intertidal burrowing crabs Australoplax tridentata and a portunid Scylla serrata sampled from estuaries on the east coast of Australia between Cairns and Brisbane. Residues of dieldrin occurred at all locations, heptachlor epoxide and DDT (principally metabolites DDD and DDE) at most, reflecting historical use. Chlordane, chlorpyrifos and endosulfan were only detected in crabs in the urban Brisbane area, and neither hexachlorobenzene (HCB) or polychlorinated biphenyls (PCBs) were quantifiable. Calculations of ambient exposures to organochlorines based on residues in crab tissues indicated that dieldrin exceeded national water quality guidelines for protection of aquatic ecosystems at all sampling locations, but exposure to DDT and its metabolites was below the threshold of concern. Concentrations of trace metals and metalloids generally reflected sediment data and likely sources.

PCDDs, PCDFs, PCBs and HCB in marine and estuarine sediments from Queensland, Australia

Concentrations of 2,3,7,8-chlorine substituted PCDDs, PCDFs, selected PCB congeners and HCB were determined in sediment samples collected from sites along the east coast of Queensland in northern Australia. PCDDs were detectable in all sediment samples while PCDFs, PCBs and HCB were mainly found in sediment samples collected from sites in the Brisbane metropolitan area. The results provide evidence that an unidentified source for higher chlorinated PCDDs exists along the Queensland coast.

Facilitated Transport of Dioxins in Soil Following Unintentional Release of Pesticide-Surfactant Formulations

Colloids such as surfactant micelles can act as transport facilitators for highly lipophilic, generally immobile contaminants in soil. Following a fire at a pesticide facility, this study investigated vertical and lateral migration of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in heterogeneous soil beneath bunded ponds, where contaminated wastewater containing high surfactant loads was stored until remediation. Initially, surface and subsurface soil was obtained during excavation, and subsequently intact cores to 5.7 m were collected. ΣPCDD/F concentrations were elevated in the wastewater (15-81 ng/L) and correspondingly in pond surface soils (6.1-61 ng/g). Maximum ΣPCDD/F concentrations were, however, observed at 2-2.5 m depth (68-130 ng/g), far below their expected mobility range based on physicochemical properties. Congener specific analysis further indicated that PCDD/F mobility was reversed, with the least water-soluble congener migrating to the greatest extent. The presence of higher chlorinated PCDD/Fs throughout a core collected in the direction of groundwater flow indicated subsequent lateral transport. These results provide field evidence for rapid vertical migration (2.4 m in <4 months) of highly lipophilic PCDD/Fs and suggest surfactant facilitated transport as the dominant transport mechanism. Quantification and evaluation of such fundamental changes in contaminant transport and fate in the presence of surfactants is required to identify areas at risk of groundwater contamination.

Effect of Exposure to Chlorobenzenes on Growth Rates of the Crab Portunus pelagicus (L)

Juvenile crabs (Portunus pelagicus) were exposed to sublethal aqueous concentrations of each of a series of chlorobenzenes (monochlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,3,4-tetra-chlorobenzene, pentachlorobenzene, and hexachlorobenzene) and the effective concentrations of each compound associated with a growth rate reduction of 50 and 10%, designated EC 50 and EC 10 , respectively, were calculated. These concentrations declined with increasing log K ow over the range 2.7-5.2 and were closely related with log K ow , molar volume, molecular free surface area, and aqueous solubility, thus providing useful QSARs. By contrast, the calculated critical body residue concentration associated with a growth rate reduction of 50% increased consistently from 1720 μmol kg -1 lipid (monochlorobenzene) to 28 000 μmol kg -1 lipid (pentachlorobenzene) and with corresponding critical volume fractions of 0.201-5.61 L toxicant L -1 lipid (x10 -3 ) (ie., 0.0201-0.561%). QSARs relating the critical body residue concentrations to the same set of descriptors as for the external exposure concentrations were developed.

Persistent organochlorines and metals in estuarine mud crabs of the Great Barrier Reef.

Contamination of the Great Barrier Reef (GBR) with metals, pesticides and persistent organic pollutants (POPs), such as DDT and dieldrin, is primarily due to effluent discharge, urban stormwater and agricultural and industrial runoff (Haynes and Johnson, 2000). Pesticides currently used in GBR catchments, including the herbicides diuron and atrazine, have been detected in water and sediments from the GBR lagoon ([Haynes et al., 2000], [Mitchell et al., 2005] and [Kapernick et al., 2006]). Contamination of GBR sediments by polyaromatic hydrocarbons (PAHs), trace metals and metalloids has also been reported near marinas and port facilities ([Smith et al., 1987] and [Reichelt and Jones, 1994]). The hydrophobic POPs are more often detected in association with biota, and measuring contaminants in the tissues of organisms is critical to demonstrate exposure and uptake in natural environments (Phillips and Rainbow, 1993). On the GBR, polychlorinated biphenyls (PCBs) have been detected in dugong tissue (Haynes et al., 1999), while the organochlorines (OCs) dieldrin, DDT and its breakdown products have been detected in crabs from a range of nearshore environments ([Russell et al., 1996], Mortimer and Cox, 1999 Mortimer, M., Cox, M., 1999. Contaminants in mud crabs (Scylla serrata) from the Maroochy River. Queensland Environmental Protection Agency Technical Report No 25. Brisbane, 19p.[Mortimer and Cox, 1999] and [Mortimer, 2000]). The mud crab Scylla serrata has great potential as a tropical biomonitoring species because of its capacity to bioaccumulate a range of contaminants such as POPs and metals ([Mortimer, 2000] and [Andersen and Norton, 2001]). S. serrata is an important target species for subsistence, commercial and recreational fisheries and males of this species have limited territorial ranges (Ryan, 2003) and are large enough to provide ample tissue for chemical analysis. Although runoff presents a potentially significant source of pesticides and trace metals to the GBR, no comprehensive survey of bioaccumulation within GBR catchments has been previously performed. This baseline report presents the concentrations of pesticides, PCBs, PAHs, metals and metalloids in S. serrata collected following the wet seasons (2004/2005 and 2005/2006) from 11 north Queensland rivers and creeks that flow into the GBR lagoon.

A cleaner river: long term use of semipermeable membrane devices demonstrate that concentrations of selected organochlorines and PAHs in the Brisbane River estuary, Queensland have reduced substantially over the past decade.

We first used semipermeable membrane devices as samplers to evaluate concentrations of organochlorines and PAHs in the Brisbane River in 1998. Here we revisit this work and repeat the study a decade later in the same season (summer), also taking account of results from a similar study involving PAHs in the summer of 2001-2002. The accumulation of organochlorines and most PAHs in the samplers in the recent assessment was substantially less than in the 1998 deployment, suggesting that the ambient concentrations of these chemicals have decreased considerably over the last decade. In all cases there was high reproducibility of the mass of chemicals accumulated in the sampler. We used performance reference compounds in the later deployment, and assuming that the kinetics were similar in both deployment periods, we estimate that the concentration of dieldrin, the organochlorine found at highest concentrations, decreased from approximately 3.9 ng/L to about 1.4 ng/L. The decrease of most other analytes of interest including DDE and DDD was greater, potentially indicating that dieldrin is still entering the Brisbane River through run-off from urban areas where it was used widely for treatment of termites until 1995. DDT use in Australia ceased in the mid 1980s.