Large-scale spatiotemporal variations, sources, and risk assessment of banned OCPs and PAHs in suspended particulate matter from the Negro river, Argentina.

Organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) threaten the environment due to their wide environmental resistance. Environmental paradigms coexist along the Negro River (NR) in Argentina, South America, which flows to the sea below the latitude of 40o S; however, this is the first environmental assessment of OCPs and PAHs in water of the NR for more than 15 years. With 21 sampling sites covering a range of 600 km of river extension, we assessed 16 OCPs and 16 PAHs in suspended particulate material (SPM) with regard to their levels, seasonality, sources, and potential biological risk assessment. Using gas chromatography-mass spectrometry and gas chromatography coupled with electron capture detection, we found an overall mean value for Σ16 OCPs of 648.56 ng. g-1, d.w. Despite a ban spanning 25 years, an increasing trend of accumulation of hexachlorocyclohexanes (HCHs) and endosulfan was shown in the lower valley. The ɑ-HCH/ɤ-HCH and ß-HCH/(ɑ + É¤)-HCH ratios indicated a prevalent usage of technical HCH over lindane and recent HCH inputs. The most abundant compound, α-endosulfan, averaged 141.64 ng. g-1, d.w. and DDX (Σ 4,4'-DDE, 4,4'-DDD, and 4,4'-DDT) averaged 99.98 ng. g-1, d.w. Winter OCP loads in the NR reflected the runoff of the heaviest pesticide application period. We estimated the total discharge of DDT into the Atlantic ocean was 96 g.day-1, added to 458 g of HCHs and 257 g of endosulfans (ɑ + ß + epoxide) adsorbed by the SPM. PAHs occurred widely along the river (38.83 ± 43.52 µg. g-1) and the highest levels coincided with locations with marked anthropogenic-related activity, such as petroleum/gas exploitation facilities. Risk quotient analysis showed a low risk posed by OCPs, but a high risk of potential effects on biota posed by the PAHs, highlighting the need for mitigation measures.

Occurrence, behavior and the associated health risk of organochlorine pesticides in sediments and fish from Bahía Blanca Estuary, Argentina.

Organochlorine pesticides (OCPs) were assessed for their occurrence, behavior and the associated human health and ecological risks in four fish species (Micropogonias furnieri, Cynoscion guatucupa, Mustelus schmitti, and Ramnogaster arcuata) and sediments from the Bahía Blanca estuary, Argentina, an important coastal environment of South America. Total OCPs values ranged from 0.86 to 6.23 ng/g dry weight in sediments and from

Seasonal distribution pattern and bioaccumulation of Polycyclic aromatic hydrocarbons (PAHs) in four bioindicator coastal fishes of Argentina.

Polycyclic aromatic hydrocarbons (PAHs) are pollutants of global concern in coastal environments. They have a wide range of biological toxicity and due to their inherent properties, can easily bioaccumulate in organisms and concentrate in the environment. This work evaluated, in an integrated way, the seasonal PAH distribution patterns in sediments and four bioindicators fish species in a highly impacted estuary of Argentina; besides, their bioaccumulation patterns were assessed for the first time as indicator of ecological risk. The highest PAH levels in fish were found for Ramnogaster arcuata with an average of 64 ng g-1 w.w., followed by Micropogonias furnieri (45 ng g-1 w.w.), Cynoscion guatucupa (28 ng g-1 w.w.), and Mustelus schmitti (16 ng g-1 w.w.). Fish presented the highest PAH levels in fall with a predominance of petrogenic PAHs in colder seasons and pyrolytic PAHs in warmer seasons. Sediments presented an average of 233 ng g-1 d.w. with the same seasonal composition pattern of the fish tissues. Additionally, the data suggested that the main source of PAHs are wastewater discharges. The bioaccumulation factor (BAF) of PAHs in the tested fishes were found to range from 0.3 to 8. The highest values were observed during fall and winter, while bioaccumulation did not occur in moist spring and summer samples, which would suggest a high biotransformation process during these seasons. Results suggested that class III of juvenile C. guatucupa and M. furnieri, and adults R. arcuata are more sensitive bioindicators of chronic PAH contamination and that their bioaccumulation is independent of the compound hydrophobicity; this could have a positively influence on the criteria used for biological monitoring programs along the Atlantic coast. In addition, the presented BAF data on the target species will serve as a useful pollution indicator for South Atlantic coastal fish.

Persistent organic pollutants (POPs) in coastal wetlands: A review of their occurrences, toxic effects, and biogeochemical cycling.

Coastal wetlands, such as mangroves, seagrass beds, and salt marshes, are highly threatened by increasing anthropic pressures, including chemical pollution. Persistent organic pollutants (POPs) have attracted attention in these particularly vulnerable ecosystems, due to their bioaccumulative, pervasive, and ecotoxic behavior. This article reviews and summarizes available information regarding current levels, biogeochemical cycling, and effects of POPs on coastal wetlands. Sediment POP levels were compared with international quality guidelines, revealing many areas where compounds could cause damage to biota. Despite this, toxicological studies on some coastal wetland plants and microorganisms showed a high tolerance to those levels. These taxonomic groups are likely to play a key role in the cycling of the POPs, with an active role in their accumulation, immobilization, and degradation. Toxicity and biogeochemical processes varied markedly along three main axes; namely species, environmental conditions, and type of pollutant. While more focused research on newly and unintentionally produced POPs is needed, mainly in salt marshes and seagrass beds, with the information available so far, the environmental behavior, spatial distribution, and toxicity level of the studied POPs showed similar patterns across the three studied ecosystems.

First evidence of polycyclic aromatic hydrocarbons in sediments from a marine protected area within Argentinean Continental Shelf.

This study evaluated for the first time, the distribution, sources, and ecological risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) in sediments collected along the northern Patagonian shelf in the Argentine Sea -included in a Marine Protected Area (MPA). Total concentration of the PAHs varied from 19.47 to 183.17 ng/g dry weight and low molecular weight compounds, such as Anthracene and Naphthalene were the dominants. The selected PAHs ratios suggested a predominance of petrogenic sources and ecotoxicological risk evaluation based on the sediment quality guidelines model, indicated that some PAHs might cause occasional adverse biological effects in the study area.

Spatial Distribution and Ecological Risk Assessment of Residual Organochlorine Pesticides (OCPs) in South American Marine Environments.

PURPOSE OF REVIEW: Organochlorine pesticides (OCPs) have been intensely used and produced in South America. Although they were banned before the year 2000 (excepting endosulfan, which has been recently banned in several countries), OCPs remain detectable in marine environments of this continent, sometimes at risky levels for biota. This manuscript summarizes studies on OCP levels in the air, water, sediment, bivalves, fish, and marine mammals of the South American coasts and open waters over the last 20 years, tackling their spatial distribution and analyzing their associated ecotoxicological risk. RECENT FINDINGS: To the best of our knowledge, this is the first study integrating all available information on current levels of OCPs in South American marine environments. The 63 researches reviewed studied punctual sites or environmental compartments. The OCP levels were higher in semi-enclosed environments such as bays and estuaries, close to large cities. In terms of individual OCPs, dichlorodiphenyltrichloroethane (DDT) and its degradation products were more abundant than other OCPs in all the environmental compartments, excepting air, for which the most abundant OCP was endosulfan. Depending on the location and the environmental matrix, hexachlorocyclohexanes (HCHs), heptachlors, mirex, and endosulfans followed DDTs. Aldrin, dieldrin and endrin, hexachlorobenzene (HCB), and chlordanes were found at very low levels in most matrices and sites, with some exceptions. Considering their potential ecotoxicological risk, most sites would be safe for biota; however, the levels of some OCPs could damage the structure and function of the communities of several coastal sites in a short or long term, mainly in southeastern Brazil and on the coast of the Argentine Pampas. Moreover, it remains to evaluate many sites potentially contaminated by OCPs.

Characterization of atmospheric and soil polycyclic aromatic hydrocarbons and evaluation of air-soil relationship in the Southwest of Buenos Aires province (Argentina).

Sixteen polycyclic aromatic hydrocarbons (PAHs) proposed by the US EPA as priority were analyzed in air and soil samples in the Southwest of Buenos Aires, Argentina, in order to study the levels, distribution, sources and fugacity ratios of PAHs, evaluating the relationship between them. For this, 10 passive air samplers (XAD-2® resin) were deployed along the area and replaced three-monthly from January to December 2015. PAHs were analyzed through gas chromatography -mass spectrometry (GC-MS). Results obtained showed that total PAHs levels (∑16) ranged from 27.97 to 1052.99 ng m-3 and from 52.40 to 2118.34 ng. g-1 d.w. for air and soil samples, respectively. The highest air- PAHs levels were registered in Bahía Blanca city (1052.99 ng. m-3, d.w.) an urban-industrial site, while the highest soil-PAHs levels were found in La Vitícola (2118.34 ng. g-1, d.w.), a rural location closed to a high traffic national route. For all sites the highest levels were observed during the winter; however, both spatial and temporal variations were only statistically significant for certain specific PAHs. Diagnostic ratios + PCA, determined dominance of pyrolytic sources. Further, data showed that source of PAHs could be attributed to vehicular and industrial emissions (observed in all periods), biomass combustion (linked mainly to warm period) and domestic emissions (linked mainly to cold period). Finally, fugacity ratios resulted <1, indicating that soil and air samples were not in equilibrium for the majority of PAHs determining a net tendency of air PAHs towards deposition while soil acted principally as a sink.

Evidence of Microplastic Ingestion by Fish from the Bahía Blanca Estuary in Argentina, South America.

The aim of this study was to assess - for the first time - the occurrence and distribution of microplastics (MPs) in the gastrointestinal tracts (GITs) of a marine commercial fish species (Micropogonias furnieri) from the Bahía Blanca Estuary (BBE) in Argentina, and to evaluate fish potential associated stress. In order to do this, juveniles were sampled using artisanal fishing arts at two sampling locations. Basic measurements of individual fish were taken (total length, total weight, weight of the liver) and GITs were subsequently removed, digested with 30% H2O2 for 5 days at 60°C, filtered on Whatman paper and then dried. Samples were observed with a stereomicroscope, and it was demonstrated that 100% of the individuals contained microplastic particles in their GITs. In total, 241 microplastic particles were removed from the GITs of all fish. They were categorized as fibers (60.8%), pellets (28.9%), fragments (8.6%) and laminas (1.4%), and they ranged in size from 0.98 to > 5 mm. The average number of particles per fish was higher than that reported in previous global marine studies. Moreover, a positive correlation between the number of MPs per fish and hepatosomatic index was found, suggesting a probable stress in their health condition. These findings provide the first and southernmost evidence of microplastic contamination in biota from the Argentinean sea, which is found in the South Atlantic sea.

Fast and Feasible Ultrasound-Assisted Pretreatment for the Determination of Organotin Compounds in Environmental Samples.

The goal of this study was to improve an already established reference method, such as the one devoted to organotin compounds determination (Reference Method for Marine Pollution Studies, No. 59, UNEP). The proposed upgrade consists of replacing the mechanical shaking by ultrasound energy and applying low temperature throughout the whole procedure. The optimization of the new operational conditions was performed by using a factorial design. Quality control was performed using a certified sediment reference material (PACS-2) for sediments (82.5-97% of recovery) and recoveries on spiked samples for suspended particulate matter (SPM) and mussels (94-100%). The proposed procedure was applied to surface sediment samples, SPM, and native bivalve mollusks (Brachidontes rodriguezii) collected in Bahia Blanca estuary, a very industrialized zone. The relative standard deviation (RSD %) of the environmental samples were less than 7.9%. It is important to note that the proposed procedure reduced the sample pretreatment time about seven times.

Organotin compounds in Brachidontes rodriguezii mussels from the Bahía Blanca Estuary, Argentina.

Levels of tributyltin and its breakdown compounds, including the first record of monobutyltin (MBT) in history for Latin America, were determined in native mussels (Brachidontes rodriguezii) by means of CG-MS, after extraction/derivatization assisted by ultrasound. The samples were collected in 2013 in Bahía Blanca Estuary (Argentina) at 6 sites, which reflect different levels of maritime activities. Total butyltins (TBts = TBT+ DBT+ MBT) levels ranged from 19.64 to 180.57ng Sn g-1 dry weight. According to the Oslo-Paris commission, the results indicated that 73.9% of mussels could be under biological effects risks associated with TBT pollution. In accordance with the calculated bioaccumulation factors, approximately 56% of samples appeared to have accumulated TBT through the sediments. All sampling sites were shown to be impacted by organotin compounds (OTCs) showing variable levels through seasons, which could be related with the variation of the water temperature. Degradation index analyses suggested aged inputs of TBT possibly under a general degradation process at the area of study. In addition, the occurrence of DBT and MBT could not be uniquely attributed to the degradation pathway of the TBT; in fact, results outlined the possible contribution of some punctual and diffuse sources at the area such as proximity to plastic industries, industrial effluents, sewage outlets and domestic wastewaters.

Distribution and human health risk assessment of PAHs in four fish species from a SW Atlantic estuary.

The aim of this study is to assess-for the first time-the concentration of the 16 polycyclic aromatic hydrocarbons (PAHs) in the muscle tissues of four fish species (Micropogonias furnieri, Cynoscion guatucupa, Ramnogaster arcuata, and Mustelus schmitti) from Bahía Blanca estuary, Argentina and to evaluate their sources, distribution, and the human health risks implicated. Considering the four species under study, mean total PAH concentrations showed the following decreasing accumulation trend: M. schmitti, R. arcuata, C. guatucupa, and M. furnieri. Low molecular weight PAHs, such as naphthalene and phenanthrene, were generally predominant, displaying properties of PAH mixtures generated from petrogenic pollution. Of the four fish species analyzed, M. furnieri was the only one that did not raise any human consumption warning. In the case of the other species, exceeding values were found above the safety human consumption guidelines. Nevertheless, the screening criteria for carcinogenic PAHs proposed by the USEPA indicated a good quality status for these fish species.

Polycyclic Aromatic Hydrocarbons in Mussels from a South American Estuary.

Bivalves, especially mussels, have been pointed as putative species to monitor polycyclic aromatic hydrocarbons (PAHs) in marine environment. After several environmental PAHs baseline reports, the present study was conducted to assess for the first time the levels of PAHs in native mussels (Brachidontes rodriguezii) collected from a critical industrialized estuary of Argentina. Under this objective, after an 18-month sampling period, 34 pools of mussels were assessed for 17 PAHs, including the 16 compounds prioritized by United States Environmental Protection Agency. By means of gas chromatography-mass spectrometry analysis, results showed total PAHs concentrations in mussel's tissue ranged from under laboratory detection limits to 482.4 ng/g dry weight. Mussel body burdens were dominated by lower molecular weight PAHs, such as phenanthrene, naphthalene, and pyrene, whereas the overall PAHs profile suggested the predominance of petrogenic sources. Finally, the potential ecotoxicological impact was evaluated by applying Environmental Assessment Criteria and benzo[a]pyrene toxic equivalent factors.

Tracing Cr, Pb, Fe and Mn occurrence in the Bahía Blanca estuary through commercial fish species.

Over the last decades the anthropogenic contamination impact has substantially increased in the Bahía Blanca estuarine area, and scarce information exists regarding metals in the biotic compartment of this estuary. Thus, fish tissues were used to evaluate metal accumulation within this aquatic environment. The study focused on the determination of Cr, Pb, Fe and Mn in the gills, liver and muscle tissues of six commercial fish species (Brevoortia aurea, Odontesthes argentinensis, Micropogonias furnieri, Cynoscion guatucupa, Mustelus schmitti and Paralichthys orbignyanus). From the results it can be summarized that C. guatucupa tends to accumulate higher metal levels in the liver tissues, mostly Cr and Fe, than the other studied species. O. argentinensis and P. orbignyanus, both permanent inhabitants of the BBE, achieved the highest metal values in the gill tissues, mostly in comparison to M. schmitti. The gill tissues were found to be the main organ of Mn and Ni accumulation for most species, whereas in general, minimum concentrations were found for all the analyzed metals in the muscle tissues. Nevertheless, and according to the guidelines, all fish species showed at least one sample with concentrations of Mn and/or Cr above the permissible levels for human consumption. Finally, it was highlighted the usefulness of selecting these fish species as bioindicators of metal pollution, since they are either permanent inhabitants of the estuary or, according to the sizes under analyses, spend much of their time in this coastal waters.

Distribution, Sources, and Potential Ecotoxicological Risk of Polycyclic Aromatic Hydrocarbons in Surface Sediments from Bahía Blanca Estuary, Argentina.

Thirty-four surface sediment samples were collected from Bahía Blanca Estuary, Argentina, to evaluate polycyclic aromatic hydrocarbon (PAH) contamination and ecotoxicity risk by applying sediment-quality guidelines (SQGs) and toxic equivalent factors (TEQ). Total concentrations of 17 parent PAHs, including the 16 United States Environmental Protection Agency priority PAHs, were measured using gas chromatography-mass spectrometry, and their levels ranged from 19.7 to 30,054.5 ng/g dry weight. The greatest values were found near the urban/industrial core and decreasing as the distance from that site increased. Molecular ratios determined mixed sources of PAHs with a slight imposition of pyrolitic over the petrogenic inputs. The ecotoxicological evaluation, based on the SQG model, showed that some of the individual PAHs were in excess of the effects range low (ERL) and the effects range median's threshold; then, predicted occasional (ERL) and frequent adverse effects over the surrounding biota at the area of study were determined. Total PAH levels were expressed as benzo-a-pyrene TEQ and compared with literature data.