Occurrence, source estimation, and risk assessment of Polycyclic Aromatic Hydrocarbons in coastal seawaters from the Quintero Industrial Complex (Valparaíso, Chile)

In the 1960s, the Quintero industrial complex was inaugurated in Chile. This began a history of dramatic anthropogenic impacts on the Chilean coast. Among the known, we could mention high atmospheric emissions of chemicals due to combustion processes and frequent oil spills. For this reason, we surveyed the concentrations of fifteen EPA_PAHs in the surface coastal waters of the Quintero Bay area in 2015. The levels found are in the range of the highest levels when reviewing the literature (0.97 μg L^-1 up to 9.84 μg L^-1). The highest levels were found in the vicinity of the industrial complex and decreased in the other two zones. The concentration of individual compounds significantly exceeds the levels recommended by the EPA (Environmental Protection Agency) and the EU water framework directive (WFD). The risk estimations revealed that PAH concentrations represent high-risk for wildlife. Molecular ratios of PAHs were used to identify the possible sources, being these were mainly of pyrogenic origin, agreeing with an origin in the combustion of wood, coal, grass, and fossil fuels. This study contributes to the first data for surface water in a country's highly impacted industrial coastal area.

Marine debris and associated organic pollutants in surface waters of Chiloé in the Northern Chilean Patagonia (42°-44°S)

We report the occurrence of plastics and associated persistent organic pollutants (POPs) in surface waters from Northern Chilean Patagonia. A total of 200 particles were found during the conducted survey. The highest number of particles found was 0.6 item m^-3. We found that 53 % of the collected particles corresponded to plastic, with an average of 0.19 ± 0.18 item m^-3. Microplastics (68 %) were the dominant size found in the area, followed by macroplastics (18 %) and mesoplastics (14 %). Most plastic particles were white (55 %) while others were <10 % each. Black and light blue represented 9 %; red, dark blue, and other colors 7 %; and green 6 %. Fragments were the most frequent shape of plastic debris (38 %), followed by Styrofoam (30 %) and fiber (27 %). Higher PBDE levels were found in the central zone, and those were higher than DDT, PeCB, HCB, and PCB levels. This study is the first report on POP occurrence in marine plastic debris from Chiloé Sea in the Northern Chilean Patagonia.

A decade later, reviewing floating marine debris in Northern Chilean Patagonia

Floating marine debris (FMD) were abundantly reported in the Northern Chilean Patagonia in 2009 where sea-based activities (mussel and salmon aquaculture) are responsible for most of them. Identifying the sources of FMD is important to take the necessary actions to diminish their abundance. In 2019 eleven transects were opportunistically conducted to evaluate the abundance, spatial distribution and composition of FMD in the same area, and to compare them with the previous study using the same methodology. FMD identified were classified into the same six categories from the previous study, however "Others" category were now the dominant one indicating that new pollutants have been increasing during the last decade. Inside the "others" category, plastics buoy and other floating devices, that normally are used by the salmon aquaculture, were the main items. Similarly than the previous study, styrofoam and domestic plastics were also the other most abundant items. In general, also, an increase in abundance compared with the previous study was found. The highest abundances were similarly found in the "Golfo de Corcovado" zone ranging from 50 to 230 items km^-2. Our results, as well as the previous study, confirm that sea-based activities are still responsible for the FMD found in the Northern Patagonia. To avoid the origin of this contamination it is urgent to implement public policies that effectively reduce FMD, and hold the aquaculture industries responsible.

Assessing levels and seasonal variations of current-use pesticides (CUPs) in the Tuscan atmosphere, Italy, using polyurethane foam disks (PUF) passive air samplers

Polyurethane foam disks (PUF) passive air samplers (PAS) were deployed over 4 sampling periods of 3-5-months (≥ 1 year) at ten urban and rural locations throughout the Tuscany Region. The purpose was to assess the occurrence and seasonal variations of ten current-use pesticides (CUPs). PUF disk extracts were analyzed using GC-MS. The organophosphates insecticides; chlorpyrifos (3-580 pg m(-3)) and chlorpyrifos-methyl (below detection limit - to 570 pg m(-3)) presented the highest levels in air, and showed seasonal fluctuation coinciding with the growing seasons. The relative proportion urban/(urban + rural) ranged from 0.4 to 0.7 showing no differences between urban and rural concentrations. Air back trajectories analysis showed air masses passing over agricultural fields and potentially enhancing the drift of pesticides into the urban sites. This study represents the first information regarding CUPs in the atmosphere of Tuscany region using PAS-PUF disk.

Assessing Polycyclic Aromatic Hydrocarbons (PAHs) using passive air sampling in the atmosphere of one of the most wood-smoke-polluted cities in Chile: The case study of Temuco

This study addresses human health concerns in the city of Temuco that are attributed to wood smoke and related pollutants associated with wood burning activities that are prevalent in Temuco. Polycyclic Aromatic Hydrocarbons (PAHs) were measured in air across urban and rural sites over three seasons in Temuco using polyurethane foam (PUF) disk passive air samplers (PUF-PAS). Concentrations of ΣPAHs (15 congeners) in air ranged from BDL to ∼70 ng m(-3) and were highest during the winter season, which is attributed to emissions from residential heating by wood combustion. The results for all three seasons showed that the PAH plume was widespread across all sites including rural sites on the outskirts of Temuco. Some interesting variations were observed between seasons in the composition of PAHs, which were attributed to differences in seasonal point sources. A comparison of the PAH composition in the passive samples with active samples (gas+particle phase) from the same site revealed similar congener profiles. Overall, the study demonstrated that the PUF disk passive air sampler provides a simple approach for measuring PAHs in air and for tracking effectiveness of pollution control measures in urban areas in order to improve public health.

Accumulation of polycyclic aromatic hydrocarbons by lichen transplants: Comparison with gas-phase passive air samplers

This study compared the accumulation of 16 polycyclic aromatic hydrocarbons (PAHs) in samples of the lichen Evernia prunastri exposed for 3 months in and around an industrial area of S Italy with that in co-located passive gas-phase air samplers. The results showed a strong linear correlations (R=0.96, P<0.05) between total PAHs in lichens and in passive samplers, clearly indicating that lichen transplants may provide direct quantitative information on the atmospheric load by total PAHs, allowing translation of lichen values into atmospheric concentrations. To the best of our knowledge this is the first study reporting such a correlation with gas-phase passive air samplers.

Levels of Persistent Organic Pollutants (POPs) in sediments from Lenga estuary, central Chile

Superficial sediments from Lenga estuary in the VIII region of central Chile were analysed for Polychlorinated Biphenyls (PCBs) and Hexachlorobenzene (HCB). Organic carbon (OC) analysis was also performed and the statistical correlations (Pearson correlations) between compounds were also tested. Results showed the total PCB concentrations (ng g(-)(1)d.w.) fluctuated from ∼ 20 to 10,000. These levels are higher than those reported in other coastal sediments of the world. The PCB profile was dominated by middle to highly chlorinated congeners (6-Cl=40% and 7-Cl=30%). HCB concentrations (ng g(-)(1)d.w.), were lower than the PCBs and, fluctuated between 1 (at L1) and 870 (at L4). OC values ranged from 1% (L1) to 7% (L4) showing a significant positive correlations between OC% and PCBs (r=0.86; p<0.05) and for HCB (r=0.71). These results are an important contribution to knowledge of levels of POPs levels in coastal Chilean environments.

GRIF-1–kinesin-1 interactions: a confocal microscopy study

GRIF-1 [GABAA (γ-aminobutyric acidA) receptor interacting factor-1] is a member of a coiled-coil family of proteins thought to function as adaptors in the anterograde trafficking of organelles utilizing the kinesin-1 motor proteins to synapses. To study in more detail the molecular interaction between GRIF-1 and the kinesin-1 family member KIF5C, fluorescent yellow- and fluorescent cyan-tagged GRIF-1, KIF5C, the KIF5C MD (motor domain) and the KIF5C NMD (non-motor domain) fusion proteins were generated. Each was characterized with respect to size and ability to co-associate by immunoprecipitation following expression in HEK-293 (human embryonic kidney 293) cells. Further, their distribution in transfected HEK-293 and transformed African green monkey kidney (COS-7) cells was analysed by confocal microscopy. The fluorescent GRIF-1 and KIF5C fusion proteins were all found to behave as wild-type. Double GRIF-1/KIF5C transfectants revealed co-localization. The GRIF-1/KIF5C and GRIF-1/KIF5C NMD double transfectants showed different subcellular distributions compared with single GRIF-1, KIF5C or KIF5C NMD transfections. These studies confirm the association between GRIF-1 and kinesin-1 NMDs. Fluorescence resonance energy transfer studies are ongoing to characterize this interaction in more detail.

First report on chlorinated pesticide deposition in a sediment core from a small lake in central Chile

This paper presents a first report on chlorinated pesticide deposition analyzed through sedimentary records in a small mesotrophic lake (Chica de San Pedro) in central Chile. The sediment core was sliced and dated using 210Pb, 137Cs and pollen analyses. Organochlorine pesticides were analyzed by gas chromatography with electron capture detection (GC-ECD). From these results, pesticide deposition over the last 50 years was estimated. No pesticides were detected below the 1940 slice of the core. Concentrations were in the range 0.640-1.4 ng/g d.w. for total DDTs, 0.046-0.362 ng/g d.w. for lindane and 0.015-0.310 ng/g d.w. for alpha-hexachlorohexane. Highest concentrations of pp'DDT were found in 1993-1996 and higher concentrations of pp'-DDE and pp'-DDD were found in the seventies (1972-1978). Total organic carbon (TOC) normalized data were used for statistical analysis. Although significant correlation was observed between concentrations of DDE and DDD, no correlation was found for DDT, suggesting that it had a different source. Factorial analysis grouped DDE together with DDD, while DDT was grouped together with gamma- and alpha-HCH. Total DDT fluxes were highest during the 1970s, while those for HCHs have been increasing in the 1990s. In Chile, organochlorine compounds were banned in 1985, and the historical deposition patterns seem to indicate that such measures have been effective. On the other hand, results point out a relatively new occurrence of pp'-DDT in the watershed, but the source remains unknown.