Sediments to be dredged as part of the installation of a harbor crossing in Sydney, Australia, contained measurable concentrations of dioxin-like compounds. To assess the suitability of these sediments for ocean disposal, a defensible sediment quality guideline value (SQGV) for dioxin-like compounds, expressed as pg toxic equivalent (TEQ)fish /g dry weight, was required. There were deemed to be too many uncertainties associated with a value derived using effects data from field studies. A similar issue was associated with values based on equilibrium partitioning from sediment to pore water, largely associated with the wide range of reported sediment:water partition coefficients. Greater certainty was associated with the use of a tissue residue approach based on equilibrium partitioning between sediment and organisms determined using tissue concentrations in fish, the most sensitive aquatic biota, and biota:sediment accumulation factors. The calculation of an appropriate SQGV used data for dioxin-like compounds in both fish and sediments from Sydney Harbor. A conservative SQGV for dioxin-like compounds of 70 pg TEQ/g dry weight was deemed to be adequately protective of biota that might be exposed to these contaminants in sediments at the ocean spoil ground. The approach is transferable to similar situations internationally. Environ Toxicol Chem 2023;42:257-271. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

BACKGROUND: With the growing prevalence of obesity, an increased number of bariatric surgeries are being performed. Lipophilic persistent organic pollutants (POPs) are stored in adipose tissue, and an increased release of lipophilic POPs into the blood circulation may occur following rapid weight loss such as after bariatric surgery.
OBJECTIVE: To evaluate and compare POP levels in serum before and after bariatric surgery, and to assess if the POP levels exceeded health based guideline values, with particular focus on women of childbearing age (WCBA).
METHODS: Serum samples from 63 patients before and one year after bariatric surgery were analysed for organochlorine pesticides (OCPs); polychlorinated biphenyls (PCBs); and brominated flame retardants (BFRs).
RESULTS: Mean weight loss one year after surgery was 32.1kg. The levels of all the analysed POPs in serum increased during the study period. Median levels of dichlorodiphenyldichloroethylene (p,p\'-DDE), hexachlorobenzen (HCB) and PCB-153 increased from 90.2ng/g lipid weight (lw) to 158.5ng/glw, from 21.1ng/glw to 36.4ng/glw and from 48.7ng/glw to 71.5ng/glw, respectively. The highest percentage increase was observed for PCB -138, with 83.1%. BFRs were detected in low sample numbers and at low levels. Guideline values for ΣPCB6 in serum were exceeded for 5% of the participants.
CONCLUSIONS: Weight loss after bariatric surgery resulted in increases of POPs levels in serum between 46.7%-83.1%. Guideline values for ΣPCB6 in serum were exceeded for 5% of the participants. For WCBA, the possible transfer of comparable levels to infants warrants further attention.

Eight software applications are compared for their performance in estimating the octanol-water partition coefficient (Kow), melting point, vapor pressure and water solubility for a dataset of polychlorinated biphenyls, polybrominated diphenyl ethers, polychlorinated dibenzodioxins, and polycyclic aromatic hydrocarbons. The predicted property values are compared against a curated dataset of measured property values compiled from the scientific literature with careful consideration given to the analytical methods used for property measurements of these hydrophobic chemicals. The variability in the predicted values from different calculators generally increases for higher values of Kow and melting point and for lower values of water solubility and vapor pressure. For each property, no individual calculator outperforms the others for all four of the chemical classes included in the analysis. Because calculator performance varies based on chemical class and property value, the geometric mean and the median of the calculated values from multiple calculators that use different estimation algorithms are recommended as more reliable estimates of the property value than the value from any single calculator.