Dioxins/furans and polychlorinated biphenyls (PCBs) in Dugongs from the Thailand Coast

Concentrations of legacy persistent organic pollutants and naturally produced MeO-PBDEs in dugongs (Dugong dugon) from Moreton Bay, Australia

Dugongs (Dugong dugon) are an iconic and strictly herbivorous species. They inhabit coastal areas, which brings them in contact with urban and agricultural pollutant sources, yet their exposure and susceptibility to environmental pollutants is still largely unknown. The goal of this study was to investigate the presence of several legacy compounds such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and pesticides as well as naturally produced MeO-PBDEs in male and female dugongs from Moreton Bay (n = 24), a semi-enclosed embayment close to Australia's third largest city, Brisbane. Results show that concentrations of all investigated compounds are low in general (<120 ng/g lipid weight) and below known toxicity thresholds established for marine mammals. However, concentrations found in this study are higher or comparable to concentrations in dugongs outside Moreton Bay or in sirenians worldwide. No temporal trends for POPs from 2001 until 2012 were found for adult animals suggesting that environmental changes are only slowly reflected in dugongs. Finally, pollutant profiles in dugongs are limited to the most persistent PCBs, pesticides and PBDEs that also dominate POP profiles in other marine mammal species in general.

PCDD/F and PCB levels in different tissues from dugongs (Dugong dugon) inhabiting the Queensland coastline

Previous studies on PCDD/Fs and PCBs in dugong (Dugong dugon) blubber reported unexpectedly elevated TEQ levels. This study analysed archived blubber, muscle, liver and faeces obtained from dugongs from two areas along the Queensland coast. All samples showed detectable levels of PCDDs and PCBs, while PCDFs were consistently near or below LOQ. PCDD levels in dugongs contributed to a large proportion (<95%) of sum TEQ levels in all tissues (blubber: 6.7-38 pg g^-1 lw, muscle: 5.7-96 pg g^-1 lw, liver: 3.3-42 pg g^-1 lw, faeces: 203 pg g^-1 lw). Liver/blubber tissue ratios show that PCDDs are preferentially accumulated in the liver with higher degree of chlorination. The same trend was not so obvious with PCBs, which occasionally showed higher hepatic sequestration of lower chlorinated PCBs such as PCBs 28 and 77. PCDD congeners were dominated by OCDD which is similar to the profiles from the dugongs' food source, namely sediment and seagrass.

Serum biochemistry reference intervals of live wild dugongs (Dugong dugon) from urban coastal Australia

BACKGROUND

Little is known about the baseline clinical pathology of the dugong (Dugong dugon), a vulnerable marine mammal found in tropical coastal marine systems.

OBJECTIVES

The purpose of the study was to collect and determine reference intervals (RI) for select serum biochemical variables for dugongs, and to analyze differences between males and females and different age groups.

METHODS

Reference intervals were established from 103 apparently healthy, wild-caught dugongs for 31 analytes using a Beckman Coulter AU400 Automated Chemistry Analyzer and an Olympus AU680 Chemistry-Immuno Analyzer.

RESULTS

Significant differences (P < .05) in some of the variables were found related to size class, sex, and pregnancy status. Adult dugongs had higher serum sodium, potassium, bicarbonate, glucose, and l-lactate concentrations and higher anion gap, compared to sub-adults. Male dugongs had higher triglyceride and l-lactate concentrations than females. Pregnant females displayed higher l-lactate levels compared to nonpregnant animals. Statistical differences in variables within the population contributed to better understanding of the physiologic differences between cohorts. Some serum biochemistry changes observed in this study here also potentially include some effects of pursuit on dugongs (eg, higher l-lactate); however, as all dugongs were subject to similar capture and handling, serum biochemistry RI should be considered as normal for captured dugongs.

CONCLUSIONS

The serum biochemical RI documented here are considered representative of a population of healthy captured dugongs. They provide a baseline for health surveillance of this and other dugong populations.

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in sediment and mussel samples from Kentucky Lake, USA

Sediment and mussel tissues from the Kentucky Dam Tailwater (KDTW) and Ledbetter Embayment (LE) of Kentucky Lake, Kentucky, USA, were analyzed to examine the presence of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non-, mono-, and di-ortho-chlorine-substituted polychlorinated biphenyls. Concentrations of target compounds varied with locations and sample matrices. In general, KDTW sediment samples contained slightly higher amounts of PCDD/DFs (average: 1100, range: 120-2400) than the LE sediments (average: 920, range: 580-1300) on a pg/g dry wt (dw) basis. Dioxin-like PCBs in KDTW were (average: 550, range: 70-2,000) higher than in LE (average: 320, range: 44-1000) on a ng/g dw basis. In contrast, mussel tissues had greater concentrations of PCDD/DFs in LE (average: 6500, range: 2200-13,000) than in KDTW (average: 3500, range: 2500-4800). Dioxin-like PCBs were slightly higher in KDTW (average: 76, range: 18-100) than in LE (average: 49, range: 24-96) on a ng/g fat wt basis. Biota sediment accumulation factors (BSAFs) were calculated using tissue concentrations and sediment concentrations based on dry weight. PCDD/DFs BSAF was in the range of 0.21-25 in LE and 0.093-13 in KDTW. 1,2,3,7,8,9-HxCDF in LE and 2,3,7,8-TCDF in KDTW had a greater BSAF, while BSAF for dioxin-like PCBs ranged from 0.84 to 13 in LE and from 2.3 to 12 in KDTW in which PCB-169 had the greatest BSAF in LE and PCB-167 in KDTW. Toxic equivalency (TEQ) was greatest in mussel from LE (mean: 193 pgTEQ/g fat wt) followed by mussel from KDTW (32 pgTEQ/g fat wt), sediment in KDTW (13 pgTEQ/g dry wt), and sediment in LE (7.6 pgTEQ/g dry wt). In general, PCDD/DF had a greater contribution to toxicity in mussels, while dioxin-like PCBs had a greater contribution to toxicity in sediment at both locations.

Concentrations of organotin compounds in tissues and organs of dugongs from Thai coastal waters

Concentrations of butyltin (BT) and phenyltin (PT) compounds were measured in organs and tissues of dugongs (Dugong dugon) from the coastal waters of Thailand. Concentrations of BTs and PTs were in the range of 14-14,468 and <1-30 microg kg(-1)(detection frequency: 79%), respectively. Although concentrations of BTs in dugongs were higher then reported concentrations in cetaceans and pinnipeds, PTs were lower in dugongs. In half of the dugongs in which measurements were made, the concentration of BTs in the liver was the highest among the all the tissues and organs tested. Dibutyltin (DBT) or monobutyltin (MBT) was found to be the dominant compounds among the BTs. The distribution in the body of PTs was not clear because of the lower levels of this compound. TPT was the dominant compound among PTs. The coastal area of Thailand is located off the Gulf of Thailand and the Andaman Sea. Concentrations of organotin (OT) compounds in dugongs collected from the Gulf of Thailand were compared to those from the Andaman Sea. No significant differences in BT or PT concentrations were observed between the two areas (p < 0.05). The concentrations of BTs and PTs in the livers of dugongs were decreased between 1998 and 2002, suggesting a decrease in OT concentrations in the surrounding environment.

Impact of FEBRA (fermented brown rice with Aspergillus oryzae) intake and concentrations of PCDDs, PCDFs and PCBs in blood of humans from Japan

Impact of FEBRA (fermented brown rice with Aspergillus oryzae, a rich dietary fiber) intake on the concentrations of polychlorinated-biphenyls (PCBs), -dioxin-like polychlorinated biphenyls (DLPCBs), -dibenzo-p-dioxins (PCDDs), and -dibenzofurans (PCDFs) in blood of nine married Japanese were studied for 2 years. Concentrations of total PCBs (average+/-standard deviation) were greater 326,000+/-263,000 and 207,000+/-89,000 in FEBRA-intake and non-FEBRA-intake groups, respectively, on pg/g lipid (from now onwards data expressed on pg/g lipid). DLPCBs were second major contaminants 94,000+/-77,000 and 60,000+/-28,000, orderly in FEBRA-intake and non-FEBRA-intake groups. The concentrations of PCDD/DFs were several orders of magnitude lower than those of PCBs, whereas PCDDs were greater (433+/-233 and 512+/-511, in FEBRA-intake and non-FEBRA-intake groups, respectively) than PCDFs (56+/-50 and 43+/-35). Calculated toxic equivalency (TEQ) concentrations were 34+/-24 and 23+/-10 in FEBRA-intake and non-FEBRA-intake groups, respectively. In order to corroborate the impact of FEBRA, the changes of PCDD/DFs and PCB concentrations for 0.5-year, 1-year, 1.5-year, and 2-year samples were estimated from average concentration of 1-day before study commences and 1-week study samples. The results explicit FEBRA-intake group eliminated 7%, 33%, 45%, 36%, and 26% and non-FEBRA-intake group eliminated 8%, 28%, 36%, 31%, and 20% of DLPCBs, PCDDs, PCDFs, PCDD/DF TEQ and total TEQ, respectively. This study is the first of its kind showing the possible elimination of PCDDs, PCDFs and their TEQ in humans from Japan after the consumption of FEBRA.