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.

Atmospheric PAHs in rural, urban, industrial and beach locations in Buenos Aires Province, Argentina: sources and health risk assessment.

The first atmospheric PAHs levels and associated inhalation cancer risk were assessed over southwest Buenos Aires region by deploying PUF disk PAS samplers. Eight sampling location included coastal zones, touristic beaches, and rural inland areas were considered. PUF disks were fortified with surrogate standards and extracted by automated Soxhlet prior to GC-MS analysis. Σ16 PAHs ranged from 1.13 to 44.5 ng m-3 (10.3 ± 9.8), while urban locations showed up to 10 times higher PAH levels than rural or beach locations. Direct sources of PAHs, such as intensive vehicle traffic, heating, and general combustion activities, were identified. PAHs with four to six rings (46.62%) were predominantly Flt, Pyr, BbF, and BkF, and carcinogenic risk was expressed by BaP (0.10 ± 0.07 ng m-3) and BaPTEQs (0.26 ± 0.22 ng m-3). Inhalation ECR (2.23E-5, WHO) presented the lowest risk at beach locations. Molecular ratios and PCA showed a strong dominance in pyrolytic sources, such as biomass and coal combustion, with a particular signature in fires at inland locations. Overall, this study demonstrated that PUF disk passive air sampling provided a sound and simple approach for tracking air PAHs, their sources and public health risks, bringing a cost-effective tool for pollution control measures, even at small and remote towns. This is particularly relevant in extensive countries with medium or low income, such as Argentina.

Butyltin compounds in sediments of the Bahía Blanca estuary, Argentina.

Systematic measurements of both Tributyltin (TBT) and Dibutyltin (DBT) in sediments along different locations in the inner zone of Bahía Blanca estuary were done. Two samples were taken near the main dry dock facility, at Puerto Belgrano naval base, in Argentina. TBT concentrations from non-detected to 170.3 ng Sn g(-1) were measured in the inner region of the estuary, and higher one of 3,288 ng Sn g(-1) near the dry dock at Puerto Belgrano. DBT values ranging between non-detected and 75.2 ng Sn g(-1) were obtained along the principal channel, but extreme concentration of 1,645 ng Sn g(-1) was measured at Puerto Belgrano. These values show that this estuary is affected by organotin pollution, mainly in areas of heavy shipyard activities.

Application of solid-phase microextraction combined with gas chromatography-mass spectrometry to the determination of butylated hydroxytoluene in bottled drinking water.

Butylated hydroxytoluene (BHT) is an antioxidant utilized as additive in foods and packaging plastic. Its presence in drinking water is possible if it is used as an antioxidant in the packaging plastic because it may migrate into the package's contents. A method for the determination of BHT in water by means of solid-phase microextraction and gas chromatography-mass spectrometry has been developed and evaluated with respect to the time of fiber exposure, limits of detection and quantitation, linearity and precision. Finally, the method was applied to evaluate the presence of this substance in samples of mineral and mineralized bottled drinking water, and it appeared to be present in seven out of a total of fifteen commercial brands.