Spatial and temporal distribution of perfluoroalkyl substances (PFAS) detected after an aqueous film forming foam (AFFF) spill.

In 2015, > 460,000 L of aqueous film-forming foam (AFFF) and fire suppressors containing per- and polyfluoroalkyl substances (PFAS) were used to combat a fire at a petrochemical fuel storage terminal in the Port of Santos (Brazil). Sediments from seven sites were sampled repeatedly from 2 weeks to 1 year after the fire (n = 30). Æ©15PFAS concentrations ranged from 115 to 15,931 pg g-1 dry weight (dw). Perfluorooctane sulfonic acid (PFOS) was the most frequently detected compound with concentrations ranging from 363 to 4517 (average = 1603) pg g-1dw to <47.1 to 642 (average = 401) pg g-1 dw, followed by perfluorohexanoic acid (PFHxA) (from 38.8 to 219 (average = 162) pg g-1 dw after 15 days and from <20.8 to 161 (average = 101) pg g-1 dw one year later). Together, the hydrodynamics and fire events documented in the region were important features explaining the spread of PFAS.

Occurrence and biomagnification of perfluoroalkyl substances (PFAS) in Lake Michigan fishes.

We measured perfluoroalkyl substances (PFAS) in prey and predator fish from Lake Michigan (USA) to investigate the occurrence and biomagnification of these compounds in this important ecosystem. Twenty-one PFAS were analyzed in 117 prey fish obtained from sites across Lake Michigan and in 87 salmonids collected in four lake quadrants. The mean concentration of sum (∑) PFAS above the method detection limit was 12.7 ± 6.96 ng g-1 wet weight in predator fish (all of which were salmonids) and 10.7 ± 10.4 ng g-1 in prey fish, with outlier levels found in slimy sculpin, Cottus cognatus (187 ± 12.2 ng g-1 ww). Perfluorooctanoic sulfonic acid (PFOS) was the most frequently detected and most abundant compound of the 21 PFAS, occurring in 98 % of individuals with a mean concentration of 9.86 ± 6.36 ng g-1 ww without outliers. Perfluoroalkyl carboxylates (PFCA) concentrations were higher in prey fish than in predators, with some compounds such as perfluorooctanoic acid (PFOA) being detected in higher frequency in prey fish. Besides PFOS, detection of several long-chain (C8-C12) PFCAs were observed in >80 % of the prey fish. Overall, the observed concentrations in Lake Michigan fish were lower than those reported in other Laurentian Great Lakes except for Lake Superior. Biomagnification factors (BMFs) for PFOS exceeded 1.0 (range, 1.80 to 5.12) in all predator-prey relationships analyzed, indicating biomagnification of these compounds, whereas BMFs of other long-chain PFCAs varied according to the fish species. PFAS were found in all fish species measured from Lake Michigan and commonly biomagnified from prey to predator fish, strongly suggesting a dietary connection.

Bioaccumulation of Per- and polyfluoroalkyl substances (PFASs) in a tropical estuarine food web.

The biomagnification of per- and polyfluoroalkyl substances (PFASs) was investigated in a tropical mangrove food web from an estuary in Bahia, Brazil. Samples of 44 organisms (21 taxa), along with biofilm, leaves, sediment and suspended particulate matter were analyzed. Sum (∑) PFAS concentrations in biota samples were dominated by perfluorooctane sulfonate (PFOS, 93% detection frequency in tissues; 0.05 to 1.97 ng g-1 ww whole-body (wb)), followed by perfluorotridecanoate (PFTrDA, 57%; 0.01 to 0.28 ng g-1 ww wb). PFOS precursors such as perfluorooctane sulfonamide (FOSA, 54%; 0.01 to 0.32 ng g-1 ww wb) and N-ethyl perfluorooctane sulfonamide (EtFOSA; 30%; 0.01 to 0.21 ng g-1 ww wb) were also detected. PFAS accumulation profiles revealed different routes of exposure among bivalve, crustacean and fish groups. Statistics for left-censored data were used in order to minimize bias on trophic magnification factors (TMFs) calculations. TMFs >1 were observed for PFOS (linear + branched isomers), EtFOSA (linear + branched isomers), and perfluorononanoate (PFNA), and in all cases, dissimilar accumulation patterns were observed among different trophic positions. The apparent biodilution of some long-chain PFCAs through the food chain (TMF < 1) may be due to exposure from multiple PFAS sources. This is the first study investigating bioaccumulation of PFASs in a tropical food web and provides new insight on the behavior of this ubiquitous class of contaminants.

Polychlorinated biphenyls and chlorinated pesticides in king mackerel caught off the coast of Pernambuco, northeastern Brazil: Occurrence, contaminant profile, biological parameters and human intake.

Persistent organic pollutants such as PCBs and DDTs are ubiquitous worldwide. Their lipophilic nature facilitates accumulation in fish tissues. This study investigated 182 PCB congeners and 14 organochlorine pesticides (DDTs, HCHs, chlordanes, heptachlor and mirex) in muscle and liver of king mackerel (Scomberomorus cavalla) caught off the northeastern coast of Brazil. Concentration of PCBs, DDTs and chlordanes in muscle averaged 31.5, 4.70 and 0.15ngg(-1) dry weight (dw), respectively. Mean levels of the same contaminants in liver were 145, 18.7 and 1.11ngg(-1) dw, respectively. HCHs, heptachlor and mirex were not detected in the samples. The metabolite p,p'-DDE dominated the composition of DDTs in both muscle and liver. However, a clear shift was observed in the proportions of p,p'-DDT and p,p'-DDD when comparing both tissues, suggesting metabolism in the liver. The PCBs profile revealed a depletion in mono- through tetra-CBs and an enrichment in penta- through deca-CBs. Biological parameters such as sex, maturity stage, age, body weight and total length did not influence contaminant levels in tissues. Dietary risk assessment indicated that S. cavalla from the northeastern coast of Brazil does not pose a health risk for humans.