Fate of linear alkylbenzenes released to the coastal environment near Boston Harbor

Linear alkylbenzenes in surface sediments of an estuarine and marine environment in peninsular Malaysia

Linear alkylbenzenes were determined in the surface sediments of Muar River and Pulau Merambong, Peninsular Malaysia. The concentrations ranged from 87.4 ng g^-1 to 188.1 ng g^-1 and from 67.4 ng g^-1 to 98.2 ng g^-1 of dry weight, respectively. The composition profiles of LABs were characterized, and sewage treatment levels were identified. The ratios of internal to external isomers (I/E ratios) of the linear alkylbenzenes in Muar River sediments ranged from 1.7 to 2.2, whereas those of Pulau Merambong sediments ranged from 1.6 to 1.7. The calculated LAB ratios indicated that the study areas received primary and secondary sewage effluents. The degradation of linear alkylbenzenes in Muar River ranged from 33% to 43%, and that in Pulau Merambong ranged from 33% to 34%. The higher degradation indices in Muar River are a sign of improvement in wastewater treatment.

Assessing legacy and endocrine disrupting pollutants in Boston Harbor with transcriptomic biomarkers

Within monitoring frameworks, biomarkers provide several benefits because they serve as intermediates between pollutant exposure and effects, and integrate the responses of contaminants that operate through the same mechanism of action. This study was designed to verify the use of transcriptomic biomarkers developed in our prior work (i.e., Coastal Biosensor of Endocrine Disruption; C-BED assay) on Mytilus edulis and identify additional biomarkers for legacy pollutants. M. edulis were collected from a reference site in Pemaquid, ME, USA and deployed by the Massachusetts Water Resources Authority (MWRA) at locations in and outside Boston Harbor, MA, USA: including (1) Boston Inner Harbor (IH), (2) the current outfall (OS), (3) 1 km away from the current outfall (LNB), and (4) Deer Island (DI), the site where untreated wastewater was formerly discharged into the bay. Differential gene expression was quantified with a high density microarray. Seven genes significantly correlated with whole tissue concentration of PAHs, and six genes significantly correlated with whole body concentrations of PCBs, two groups of legacy contaminants that were elevated at stations IH, OS, and DI. Enrichment analysis indicated that IH mussels had the highest induction of stress response genes, which correlated with the higher levels of contaminants measured at this site. Based on the C-BED assay gene analysis, stations IH and OS exhibited signs of endocrine disruption, which were further confirmed by incorporating the results for the C-BED assay within the Integrated Biomarker Response (IBR) approach. This study successfully demonstrated the potential use of transcriptomic biomarkers within a monitoring program to identify the presence and organismal responses to endocrine disrupting and legacy contaminant classes.

Distribution of linear alkylbenzenes as a domestic sewage molecular marker in surface sediments of International Anzali Wetland in the southwest of the Caspian Sea, Iran

Due to directly receiving high volume of untreated urban and industrial sewage and in turn transferring the pollutants to fish and back to humans, the International Anzali Wetland has been considered to be urgently registered in the Montreux Record. Hence, the present study was aimed to determine the spatial distribution of the linear alkylbenzenes (LABs) in surface sediments of the wetland and its sewage contamination situation. The surface sediments (sampling stations = 167) were collected from the western, eastern, southwest, and central regions of the wetland. The samples were extracted, fractioned, and then analyzed using gas chromatography-mass spectrometry (GC-MS). The concentration of LABs in the sediment samples revealed a range from 394.12 to 109,305.26 ng g^-1 dw. The concentrations of ΣLABs in the eastern region were significantly higher than that in the other regions. The occurrence of low ratio of internal to external isomers (I/E ratio) of LABs (from 0.65 to 1.30) and D% (from - 0.07 to 24.13) implied effluent row or poorly untreated sewage into the wetland. No correlation was observed between the detected LAB concentrations with total organic carbon (TOC) and grain size. Taken together, regional anthropogenic inputs are the controlling factors for the observed spatial distributions of ∑LABs in the International Anzali Wetland. The findings suggested that LABs are powerful indicators to trace anthropogenic sewage contamination and also highlighted the necessity of sewage treatment plants to be founded around the International Anzali Wetland, especially in the vicinity of the eastern and central regions.

Steroidal estrogen sources in a sewage-impacted coastal ocean

Estrogens are known to be potent endocrine disrupting chemicals that are commonly found in wastewater effluents at ng L(-1) levels. Yet, we know very little about the distribution and fate of estrogens in coastal oceans that receive wastewater inputs. This study measured a wide range of steroidal estrogens in sewage-impacted seawater using ultra high performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS) together with the method of standard addition. In Massachusetts Bay, we find conjugated, free, and halogenated estrogens at concentrations that are consistent with dilution at sites close to the sewage source. At a site 6 miles down current of the sewage source, we observe estrone (E1) concentrations (520 ± 180 pg L(-1)) that are nearly double the nearfield concentrations (320 ± 60 pg L(-1)) despite 9-fold dilution of carbamazepine, which was used as a conservative sewage tracer. Our results suggest that background E1 concentrations in Massachusetts Bay (∼270 ± 50 pg L(-1)) are derived largely from sources unrelated to wastewater effluent such as marine vertebrates.

Evaluation of distribution and sources of sewage molecular marker (LABs) in selected rivers and estuaries of Peninsular Malaysia

This is the first extensive report on linear alkylbenzenes (LABs) as sewage molecular markers in surface sediments collected from the Perlis, Kedah, Merbok, Prai, and Perak Rivers and Estuaries in the west of Peninsular Malaysia. Sediment samples were extracted, fractionated, and analyzed using gas chromatography mass spectrometry (GC-MS). The concentrations of total LABs ranged from 68 to 154 (Perlis River), 103 to 314 (Kedah River), 242 to 1062 (Merbok River), 1985 to 2910 (Prai River), and 217 to 329 ng g(-1) (Perak River) dry weight (dw). The highest levels of LABs were found at PI3 (Prai Estuary) due to the rapid industrialization and population growth in this region, while the lowest concentrations of LABs were found at PS1 (upstream of Perlis River). The LABs ratio of internal to external isomers (I/E) in this study ranged from 0.56 at KH1 (upstream of Kedah River) to 1.35 at MK3 (Merbok Estuary) indicating that the rivers receive raw sewage and primary treatment effluents in the study area. In general, the results of this paper highlighted the necessity of continuation of water treatment system improvement in Malaysia.

Anthropogenic waste indicators (AWIs), particularly PAHs and LABs, in Malaysian sediments: Application of aquatic environment for identifying anthropogenic pollution

Polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs) were used as anthropogenic markers of organic chemical pollution of sediments in the Selangor River, Peninsular Malaysia. This study was conducted on sediment samples from the beginning of the estuary to the upstream river during dry and rainy seasons. The concentrations of ƩPAHs and ƩLABs ranged from 203 to 964 and from 23 to 113 ng g(-1) dry weight (dw), respectively. In particular, the Selangor River was found to have higher sedimentary levels of PAHs and LABs during the wet season than in the dry season, which was primarily associated with the intensity of domestic wastewater discharge and high amounts of urban runoff washing the pollutants from the surrounding area. The concentrations of the toxic contaminants were determined according to the Sediment Quality Guidelines (SQGs). The PAH levels in the Selangor River did not exceed the SQGs, for example, the effects range low (ERL) value, indicating that they cannot exert adverse biological effects.

Application of multiple geochemical markers to investigate organic pollution in a dynamic coastal zone

Multiple geochemical markers, including aliphatic hydrocarbons (n-alkanes), linear alkylbenzenes (LABs), and polycyclic aromatic hydrocarbons (PAHs), were employed to relate sediment organic chemical pollution in the coastal zone off South China to socioeconomic development there. Concentrations of Σn-C(15-35) (n-alkanes with 15-35 carbon atoms), ΣLAB (sum of C(10) to C(13) LABs), and Σ(26) PAH (sum of 26 PAH compounds) ranged from 110 to 3,160, 11 to 160, and 26 to 600 ng/g, with medians of 730, 40, and 230 ng/g, respectively. Natural hydrocarbons were mainly derived from terrestrial higher plant waxes, and in minor amounts from aquatic plankton and bacteria. Compositions of LABs indicated that considerable amounts of poorly treated wastewater had been directly discharged or transported to the eastern and western coastal areas of Guangdong Province. In addition, anthropogenic hydrocarbons were derived largely from vehicular emissions and combustion of domestic coal and biomass and to a lesser extent from oil spills. Eastern and western coastal sediments contained higher levels of LABs but lower levels of PAHs than those of the Pearl River Estuary, a coastal area of the Pearl River Delta. This spatial pattern of organic pollution was consistent with chemical use patterns. The eastern and western regions of Guangdong Province are economically less developed than the Pearl River Delta region, where more domestic wastewater treatment plants have been built. However, greater amounts of energy are consumed in the latter region to produce more combustion-derived PAH contamination.

Assessment of aquatic wastewater pollution in a highly industrialized zone with sediment linear alkylbenzenes

Forty-five sediment samples collected from Dongjiang River, which drains one of the most industrialized and urbanized regions in South China, were analyzed for 19 linear alkylbenzene (LAB) components. The sample dry weight-based concentrations of total LABs (ΣLAB) ranged from 1.5 to 410 ng/g. Comparison of the relative abundances of n-dodecylbenzenes (or C(12) -LABs) and internal to external ratio (I/E) values in riverine sediment, wastewater, and sediment samples from the outfalls of paper mills, as well as three brands of domestic detergents obtained from the present and previous studies, implicated the occurrence of untreated wastewater in the sampling sites. Levels of ΣLAB were significantly linear correlated with those of total organic carbon (TOC) but not with those of polycyclic aromatic hydrocarbons. Multiple linear regression integrated principal component analysis indicated that 56% of LABs in wastewater in the study area were treated, but the extent of degradation of LABs was low. Finally, it is proposed that ineffective law enforcement and loopholes in the current regulations for wastewater discharge account for the substantial amount (44%) of untreated wastewater discharged in the study region.

Tracing urban sewage pollution in Chaohu Lake (China) using linear alkylbenzenes (LABs) as a molecular marker

Linear alkylbenzenes (LABs) were determined in 61 surface sediment samples from Chaohu Lake, one of the largest and most euthrophication shallow lakes in China. Amongst these samples, thirty-five were collected with a 0.05 × 0.05° latitude/longitude resolution and 26 surface sediments were obtained at three main estuaries of inflowing rivers. The total concentration of LABs (defined as ΣLAB) ranged from 18.5 to 5720 ng g(-1) dry weight. Concentrations of ΣLAB in the western region of the lake were much higher than those in the eastern region, and the highest value was at a location in the estuary of Nanfei River, indicating that substantial amounts of municipal wastewater were discharged to Chaohu Lake via riverine runoff. Low ratio of the concentrations of internal isomers versus external isomers of C(12)-LABs ((6-C(12)+5-C(12))/(4-C(12)+3-C(12)+2-C(12)) (defined as I/E) suggested that only 16% of LABs were biodegraded on average in the sediment. Therefore untreated/inadequately treated sewage was discharged into the lake. Log-based concentrations of ΣLAB were positively correlated with log-based I/E ratios. On the other hand, negative correlative relationships were found between the log-based concentrations of ΣLAB and both log-based ΣC(13)-LAB/ΣC(12)-LAB and (5-C(13)+5-C(12))/(5-C(11)+5-C(10)) ratios (referred as L/S ratio), probably implicating that the ΣC(13)-LAB/ΣC(12)-LAB and L/S ratio should be used with caution. The total amount of ΣLAB annually deposited to Chaohu Lake's sediment was estimated at 0.2 tons yr(-1), accounting for 2.4% of the total amount of LABs contained in detergents used within the entire watershed. Therefore, the majority of LABs discharged from the watershed still remained in the environmental media.

Depositional history of sedimentary linear alkylbenzenes (LABs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil)

This paper reports the reconstruction of the contamination history of a large South American industrial coastal area (Santos Estuary, Brazil) using linear alkylbenzenes (LABs). Three sediment cores were dated by (137)Cs. Concentrations in surficial layers were comparable to the midrange concentrations reported for coastal sediments worldwide. LAB concentrations increased towards the surface, indicating increased waste discharges into the estuary in recent decades. The highest concentration values occurred in the early 1970s, a time of intense industrial activity and marked population growth. The decreased LAB concentration, in the late 1970s was assumed to be the result of the world oil crisis. Treatment of industrial effluents, which began in 1984, was represented by decreased LAB levels. Microbial degradation of LABs may be more intense in the industrial area sediments. The results show that industrial and domestic waste discharges are a historical problem in the area.

The effects of silver nanoparticles on fathead minnow (Pimephales promelas) embryos

Nanoparticles are being used in many commercial applications. We describe the toxicity of two commercial silver (Ag) nanoparticle (NP) products, NanoAmor and Sigma on Pimephales promelas embryos. Embryos were exposed to varying concentrations of either sonicated or stirred NP solutions for 96 h. LC(50) values for NanoAmor and Sigma Ag NPs were 9.4 and 10.6 mg/L for stirred and 1.25 and 1.36 mg/L for sonicated NPs, respectively. Uptake of Ag NPs into the embryos was observed after 24 h using Transmission Electron Microscopy and Ag NPs induced a concentration-dependent increase in larval abnormalities, mostly edema. Dissolved Ag released from Ag NPs was measured using Inductively Coupled-Mass Spectrometry and the effects tested were found to be three times less toxic when compared to Ag nitrate (AgNO(3)). The percentage of dissolved Ag released was inversely proportional to the concentration of Ag NPs with the lowest (0.625 mg/L) and highest (20 mg/L) concentrations tested releasing 3.7 and 0.45% dissolved Ag, respectively and percent release was similar regardless if concentrations were stirred or sonicated. Thus increased toxicity after sonication cannot be solely explained by dissolved Ag. We conclude that both dissolved and particulate forms of Ag elicited toxicity to fish embryos.

Susceptibility of synthetic long-chain alkylbenzenes to degradation in reducing marine sediments

Long-chain alkylbenzenes (LCABs) synthesized for production of alkylbenzene sulfonate surfactants have been used as molecular markers of anthropogenic waste for 25 years. Synthetic LCABs comprise two classes, the tetrapropylene-based alkylbenzenes (TABs) and the linear alkylbenzenes (LABs). LABs supplanted TABs in the mid-1960s because of improved biodegradability of their sulfonated analogs. Use of LCABs for molecular stratigraphy depends on their preservation in sediments over decadal time scales. Most laboratory and field studies suggest that LABs degrade rapidly under aerobic conditions but are resistant to degradation when oxygen is absent. However, recent work indicates that LABs may not be as persistent under reducing conditions as previously thought. To assess the potential for degradation of LCABs in reducing sediments, box cores collected in 1992 and 2003 near a submarine wastewater outfall system were analyzed using gas chromatography/mass spectrometry. The TABs were effectively preserved; differences between whole-core inventories were within analytical error. By contrast whole-core inventories of the LABs decreased by about 50-60% during the same time interval. Based on direct comparison of chemical inventories in coeval core sections, LAB transformation rates are estimated at 0.07 +/- 0.01 yr(-1). These results indicate that caution should be exercised when using synthetic LCABs for reconstruction of depositional records.

Linear alkylbenzenes in riverine runoff of the Pearl River Delta (China) and their application as anthropogenic molecular markers in coastal environments

The average concentrations of SigmaLABs (sum of C10-C13-LABs) in runoff samples collected from the eight major riverine outlets of the Pearl River Delta (PRD) of China ranged from 1.4 to 6124 ng/L in the dissolved phase and from 0.01 to 11.4 microg/g dry weight in the particulate phase during March 2005-February 2006. The annual riverine flux of SigmaLABs from the PRD to the coastal ocean was estimated at approximately 14 tons/yr. The inventories of SigmaLABs in agricultural lands of Guangdong Province ranged from 313 to 1825 kg/yr. The early and late rice fields were the major sink of LABs, accounting for approximately 68% of total LABs inventory in agricultural lands. The social-economically estimated annual discharge of LABs from household detergents in the PRD was approximately 696 tons/yr, more than an order of magnitude higher than that estimated from field measurements (about 14 tons/yr), which was attributed to several factors.

Distribution of polycyclic aromatic hydrocarbons (PAHS) and phenolic endocrine disrupting chemicals in South and Southeast Asian mussels

A comprehensive monitoring survey for polycyclic aromatic hydrocarbons (PAHs) and phenolic endocrine disrupting chemicals (EDCs) utilizing mussels as sentinel organisms was conducted in South and Southeast Asia as a part of the Asian Mussel Watch project. Green mussel (Perna viridis) samples collected from a total of 48 locations in India, Indonesia, Singapore, Malaysia, Thailand, Cambodia, Vietnam, and the Philippines during 1994-1999 were analyzed for PAHs, EDCs including nonylphenol (NP), octylphenol (OP) and bisphenol A (BPA), and linear alkylbenzenes (LABs) as molecular markers for sewage. Concentrations of NP ranged from 18 to 643 ng/g-dry tissue. The highest levels of NP in Malaysia, Singapore, the Philippines, and Indonesia were comparable to those observed in Tokyo Bay. Elevated concentrations of EDCs were not observed in Vietnam and Cambodia, probably due to the lower extent of industrialization in these regions. No consistent relationship between concentrations of phenolic EDCs and LABs were found, suggesting that sewage is not a major source of EDCs. Concentrations of PAHs ranged from 11 to 1,133 ng/g-dry, which were categorized as "low to moderate" levels of pollution. The ratio of methylphenanthrenes to phenanthrene (MP/P ratio) was >1.0 in 20 out of 25 locations, indicating extensive input of petrogenic PAHs. This study provides a bench-mark for data on the distribution of anthropogenic contaminants in this region, which is essential in evaluating temporal and spatial variation and effect of future regulatory measures.

Occurrence and degradation of butyltins and wastewater marker compounds in sediments from Barcelona harbor, Spain

Contamination of Barcelona harbor sediments was assessed by the quantitative determination of butyltins (TBT, DBT and MBT) and surfactant intermediates, namely linear alkylbenzenes (LABs) and nonylphenols (NPs), as markers of urban and industrial wastewater contamination, respectively. Degradation indexes of TBT and LABs were calculated. Tributyltin predominated in the whole area over its degradation products, ranging from 98 to 4702 ng Sn/g. These elevated concentrations reveal a persistent historical contamination and a moderate degradation (BT(deg)). Moreover, the high LAB concentrations (1.2-53.1 microg/g) compared to the relatively low NP levels (3.8-72.0 ng/g) suggest a predominance of urban over industrial wastewater inputs, although a significant correlation (r(2) = 0.82, N = 12, P = 0.001) between LABs and NPs was found. Stormwater runoff and combined sewer overflows (CSO) were likely the most possible sources for both surfactant intermediates. The high degradation index values obtained for LABs could indicate an improvement in the wastewater management reducing its recent discharge into the Barcelona harbor area.

Alkylbenzenes in mussels from South and South East Asian coasts as a molecular tool to assess sewage impact

Alkylbenzenes, molecular markers of sewage, were measured in 34 green mussels collected from India, Indonesia, Malaysia, Thailand, Cambodia, Vietnam, and the Philippines together with blue mussels collected from Tokyo Bay, Japan. Linear alkylbenzene (LAB) concentrations in South and South East Asian countries ranged from 10 to 1,640 ng-sigmaLAB/g-dry tissue. In some populous cities, LAB concentrations were similar or higher than those found in northern Tokyo Bay which is heavily impacted by sewage effluents. I/E ratios (a ratio of internal to external isomers of LABs) in the South and South East Asian countries (1-3) were much lower than those in Tokyo Bay (3-8), indicating sewage discharged in the coastal zone is poorly treated (e.g., raw sewage and/or primary effluents). Alkylbenzenes with branched alkyl chains, tetrapropylene-based alkylbenzenes, were also detected in mussels from Indonesia and Philippines. This "tell-tale" sign indicates that poorly degradable detergents are still in use in this area, although they have long been phased-out in many industrialized countries.

Dynamic colloid--water partitioning of pyrene through a coastal Baltic spring bloom

Colloidal organic particles constitute the dominant portion of particulate organic matter in surface seawater, but their influence on the phase speciation and bioavailability of hydrophobic organic compounds (HOCs) is sparsely evaluated. Studies on colloid-water partitioning have been focused on other regimes and have largely been performed on chemically defined subportions of total colloids such as the humic fraction. Available estimates of colloid-water partition coefficients (Kcoc) are highly variable and not easily explained by regularly applied Kow-Koc relationships. Here, pyrene was partitioned to bulk natural colloids isolated using cross-flow ultrafiltration techniques from the surface water of a coastal bay. A key objective was to elucidate biogeochemical controls on the changing colloid-sorbent qualities over the course of the dynamic allochtonous-autochtonous transition of a well-constrained boreal coastal spring bloom. The pyrene Kcoc was found to decrease from 12.9+/-0.9 x 10(3) Lw/kg(oc) in the terrestrial runoff dominated regime to values around 2.9+/-0.7 x 10(3) Lw/kg(oc), once phytoplankton production became the governing source of organic matter to the surface waters. The changing Kcoc was well correlated with the molar extinction coefficient at 280 nm of the colloidal organic carbon. This study supports other reports of an improved prediction of HOC phase speciation through this simple molecular proxy of the "quality" of organic sorbents. While being poor sorbents on a carbon atom basis, relative to soils and sediments, coastal marine colloids, by their shear abundance, may significantly attenuate the truly dissolved exposures of HOCs with log Kow above 5.