Microplastics from headwaters to tap water: occurrence and removal in a drinking water treatment plant in Barcelona Metropolitan area (Catalonia, NE Spain).

Nowadays, the presence of microplastics in drinking water is of concern worldwide due to potential impacts on human health. This paper has examined the presence of microplastics along the Llobregat river basin (Catalonia, Spain) and studied their behaviour and elimination along the drinking water treatment plant (DWTP). Due to different water composition, different sampling and sample preparation protocols were used to determine microplastics from river water and in the DWTP. Identification of microplastics of size range from 20 µm to 5 mm was performed by fourier-transform infrared spectroscopy (FTIR). Microplastics were detected in 5 out of 7 points along the Llobregat basin, with concentrations ranging between non-detected and 3.60 microplastics/L. In the intake of the DWTP, the mean concentration was 0.96 ± 0.46 microplastics/L (n=5), with a predominance of polyester (PES) and polypropylene (PP) and at the outlet the mean concentration was of 0.06 ± 0.04 microplastics/L with an overall removal efficiency of 93 ± 5%. Sand filtration was identified as the key stage in microplastic removal (78 ± 9%). Furthermore, the results showed that ultrafiltration/reverse osmosis (advanced treatment) is more effective for microplastic removal than ozonation/carbon filtration stage (upgraded conventional treatment). In addition, a preliminary migration test of the different materials used in the DWTP has been performed to identify potential sources of microplastics in each treatment step.

Influence of persistent organic pollutants on the endocrine stress response in free-living and captive red kites (Milvus milvus).

Persistent organic pollutants (POPs) have the potential to impair the endocrine regulation of organisms and alter their ability to respond to environmental changes. We studied whether polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) affected the endocrine regulation of free-living and captive red kites (Milvus milvus) through studying the dynamics of corticosterone (CORT) and dehydroepiandrosterone (DHEA). We sampled migratory free-living kites coming from northern Europe and captive kites born in a rehabilitation center in Spain. We used body feathers from the interscapular region as a minimally-invasive and integrative matrix. The most abundant compound detected in free-living kites was 4,4'-dichlorodiphenyldichloroethylene (4,4'-DDE; 6.10 ±â€¯1.56 ng g-1 dw feather) followed by CB-153 (3.10 ±â€¯0.63 ng g-1 dw feather) and CB-180 (2.43 ±â€¯1.08 ng g-1 dw feather). In captive kites, the most abundant compounds were 4,4'-dichlorodyphenyltrichloroethane (4,4'-DDT; 2.38 ±â€¯1.30 ng g-1 dw feather), CB-153 (2.15 ±â€¯0.47 ng g-1 dw feather) and hexachlorobenzene (HCB; 2.03 ±â€¯0.45 ng g-1 dw feather) at similar concentrations. Free-living kites showed higher levels of 4,4'-DDE and CB-180 in comparison to captive kites. Age influenced HCB and CB-101 levels, whereas body mass was inversely related to CB-180 and 4,4'-DDT. Interestingly, captive kites showed a ratio DDT/DDE higher than 1 suggesting a relatively recent exposure of DDT, in contrast to free-living kites. Regarding hormonal levels, free-living kites showed higher levels of CORT (3.30 ±â€¯0.22 pg mm-1 feather) than captive (2.40 ±â€¯0.16 pg mm-1 feather), reflecting higher allostatic load. In addition, a positive association between PCBs and DDTs and adrenal hormones was found in free-living kites, suggesting an increase of CORT as a response of the endocrine system to cope with stressors and a subsequent elevation of DHEA to ameliorate the potential negative effects that high CORT levels could cause to the organism.

Presence and impact of Stockholm Convention POPs in gull eggs from Spanish and Portuguese natural and national parks.

The aim of the present work was to comparatively assess the occurrence and impact of persistent organic pollutants (POPs) in nine natural and national parks from Spain and Portugal using gull eggs (Larus michahellis and L. audouinii) as bioindicators of environmental contamination. Sampling was performed during the breeding season of 2016. Compounds studied include polychlorinated biphenyls (PCBs), organochlorinated pesticides (OC pesticides), perfluorooctane sulfonic acid (PFOS) and polybrominated diphenyl ethers (PBDEs), and were analyzed using mass spectrometric based techniques. The results showed a high contamination by PCBs in all colonies, with total levels ranging from 59 to 1278ng/g wet weight (ww), despite their use is not currently authorized. OC pesticides were also present in all colonies, with a high incidence of 4,4'-DDE in gull eggs at levels up to 218±50ng/g ww in L. michahellis and 760±412ng/g ww in L. audouinii from the Ebro Delta natural park. PBDEs and PFOS were also detected at levels up to 91.7±21.3ng/g ww, which can be attributed to a more recent use. Except for PBDEs, the POP levels in eggs from L. audouinii were higher than in L. michahellis, presumably associated to the fish-based diet of the former. Finally, the effect of POP levels on eggshell parameters (volume, eggshell thickness and desiccation index) were investigated for each colony and gull species in order to evaluate the egg viability and, therefore, the reproduction success.