Occurrences of UV filters, endocrine disruptive chemicals, alkyl phenolic compounds, fragrances, and hormones in the wastewater and coastal waters of the Antarctica.

We present a simplified status description of the prevalence and occurrences of organic micropollutants including endocrine disruptive chemicals (EDCs), therapeutic drugs, hormones, fragrances and ultraviolet (UV) filters in the wastewaters and the adjacent coastal oceans in the Northern and Southern Antarctica. Different treatment technologies adopted in the research stations and their efficacy in removing pharmaceuticals and personal care products (PPCPs) are reviewed. Till date, 56 PPCPs are reported in the wastewaters of Antarctic research stations, and 23 in the adjacent coastal waters and sea ice. The reported concentrations in the wastewaters are at the levels of µg L-1 for UV filters, plasticizer Bisphenol A, metabolites, antibiotics, alkyl phenolic compounds, and stimulants. Concentrations in the coastal waters and sea ice are two orders of magnitude lower than the wastewaters because of dilution and degradation. It is apparent however, that the PPCP-laden effluents discharged from the research stations contaminate them. If left unchecked, pollution of the coastal waters and sea-ice can lead to toxic levels. Through this review, we have established widespread occurrence of PPCPs in the polar coastal oceans; this study will also provide the status quo for the researchers and policymakers to seriously consider the issue and initiate remedial action in the near future. The existing substantial gaps in understanding of the impact of PPCPs on the flora and fauna of Antarctica, and the ineffectiveness of the current treatment technologies adopted by the research stations are highly evident. Future-oriented polar research should focus on protecting the pristine ecosystem by utilizing climate-sensitive, cost-effective treatment technologies.

Dissolved carbon and silica fluxes from Kali, Sharavati and Sita-Swarna rivers, Southwestern India.

Spatio-temporal behaviour of dissolved organic carbon (DOC), inorganic carbon (DIC) and silica (DSi) along the salinity gradient of three south-west Indian monsoonal estuaries are presented. This study showed both conservative and non-conservative behaviour of DOC along the salinity gradient under varying physico-chemical conditions. The gross flux of DOC arriving at the estuary from the rivers was estimated as 0.9 × 109 g/yr for Sita-Swarna river, 4.2 × 109 g/yr for Sharavati river and 5.6 × 109 g/yr for Kali river. Similarly, the net fluxes of DOC estimated beyond the estuarine zone was 5.5 × 109 g/yr (Sita-Swarna), 8.0 × 109 g/yr (Sharavati) and 7.7 × 109 g/yr (Kali). This indicates that these estuaries are the sources of organic carbon to the ocean. The DIC linearly increased towards the higher salinity with net fluxes of 38 × 109 g/yr (Sita-Swarna), 75 × 109 g/yr (Sharavati) and 97 × 109 g/yr (Kali). The combined DIC flux of Sita-Swarna, Sharavati and Kali rivers is ~8% of the total DIC fluxes received from the west flowing rivers of India, to the Arabian Sea. The DSi showed a biogenic removal of 80-85% in all the studied estuaries. From this study it is concluded that the west flowing river estuaries are net sources of DOC and DIC and net sink for DSi. Consideration of the role of west flowing rivers of peninsular India is important for the better understanding of the carbon dynamics in the river-estuary-ocean boundary.

First report of pharmaceuticals and personal care products in two tropical rivers of southwestern India.

The occurrence of selected pharmaceuticals (trimethoprim, sulfamethoxazole, chloramphenicol, bezafibrate, ceftriaxone, and naproxen) in two west-flowing tropical rivers (Swarna and Nethravati) of southwestern India is reported for the first time. Water samples were collected during the monsoon and post-monsoon seasons from river water end members and further downstream up to their confluence with the adjacent Arabian Sea. Samples were analyzed using HPLC-MS/MS. Results revealed that there were no significant seasonal variations in concentrations of target analytes in both the rivers. Of the total number of samples analyzed (n = 24), trimethoprim was detected in 100% of the samples, whereas sulfamethoxazole (SMX), chloramphenicol (CAP), ceftriaxone (CTX), and naproxen (NPX) were detected in between 91 and 58% of the samples. Bezafibrate (BZF) was not detected in the samples. Nethravathi river showed higher concentrations of pharmaceuticals than the Swarna river which may be attributed to comparatively larger human population in the basin. Possible impacts of PPCPs on aquatic life offer further scope for study.

Evaluation of selected pharmaceuticals and personal care products in water matrix using ion trap mass spectrometry: A simple weighted calibration curve approach.

A novel analytical method is presented for 12 target pharmaceutical and personal care products (PPCPs), belonging to different classes like antibiotics, non-steroid anti-inflammatory drugs, parabens, UV-filters, plasticizer, and antibacterials. The method development comprises of solid-phase extraction (SPE) with lipophilic-hydrophilic material balanced Oasis HLB cartridge, followed by reverse-phase liquid chromatography interfaced to linear ion trap tandem mass spectrometry (LC-MS/MS) with electrospray ionization. Chromatographic separation was achieved with a gradient elution of 25 min run time using 5 mM ammonium acetate buffer with pH adjustment using acetic acid. In addition, cost effective organic solvent with buffer used together as the mobile phase with Chromatopak C18 column (150 mm × 4 mm, 5-µm,) in negative ionization mode. Recoveries ranged from 61.74 % to 119.89 % for most of the compounds. Matrix-matched calibration curves were used for counterbalancing the matrix effects for all the analytes, and ibuprofen D3 internal standard was used for assessing the effectiveness of extraction technique and monitoring the recovery of sample analysis. Simple empirical weighted linear regression curve technique was adopted practically for each analysis in enhancing the analyte accuracy at lower quantification level. The 1/x2 model was selected as the best suitable model for quantification of analytes, which can be evaluated by deviation from back-calculated concentration in terms of percentage relative error (%RE). Weighted calibration curves with regression value for most of the compounds were ≥ 0.98, except triclosan with a regression value ≥ 0.93. Precision showed as % relative standard deviation (%RSD) were always below 15.0 %. Accuracy-test was evaluated by the statistical one-sample t-test and no significant difference was observed between nominal and experimental value. The limit of quantification (LOQ) ranged from 3.0 ng/mL (BP1) to 1000 ng/mL (naproxen). Finally, the validated method was used for the first time to determine target analytes in surface water samples collected from Arkavathi river flowing across southern India's Bengaluru city.

Spatio-temporal variability of trace metals and major ions in a small tropical river, southwest coast of India.

Sita, a small tropical river originating in the Western Ghats, southwestern India, was chosen for this study to understand the spatial and temporal variability of dissolved trace elements and major ions. Sampling was done in monsoon, post-monsoon and pre-monsoon seasons across the river catchment. Dissolved elements like Zn, Ni, Cu and Co showed high concentrations during monsoon which could be because of the intense chemical weathering of silicate rocks in the catchment, surface runoff and wet atmospheric deposition. In the remaining seasons, the river is fed by the groundwater and anthropogenic effluents which is contributing to higher concentrations of dissolved Pb, Fe and Cd. The results are analysed using factor analysis (SPSS 12), which helped to delineate the sources of metal assemblages. Factor 1 is dominated by major ions (Na, K, Cl, Mg, Ca), which could be naturally sourced from atmospheric deposition and weathering of rocks. Factor 2 is dominated by trace metals (Cd, Pb, Co) and sulphates (SO4) which may have anthropogenic sources such as the discharge of domestic and industrial effluents and agricultural effluents.

A review of the occurrence of pharmaceuticals and personal care products in Indian water bodies.

Little information exists on the occurrence and the ultimate fate of pharmaceuticals in the water bodies in India despite being one of the world leaders in pharmaceutical production and consumption. This paper has reviewed 19 published reports of pharmaceutical occurrence in the aquatic environment in India [conventional activated sludge wastewater treatment plants (WTPs), hospital WTPs, rivers, and groundwater]. Carbamazepine (antipsychoactive), atenolol (antihypertensive), triclocarban and triclosan (antimicrobials), trimethoprim and sulfamethoxazole (antibacterials), ibuprofen and acetaminophen (analgesics), and caffeine (stimulant) are the most commonly detected at higher concentrations in Indian WTPs that treat predominantly the domestic sewage. The concentration of ciprofloxacin, sulfamethoxazole, amoxicillin, norfloxacin, and ofloxacin in Indian WTPs were up to 40 times higher than that in other countries in Europe, Australia, Asia, and North America. A very few studies in Indian rivers reported the presence of ciprofloxacin, enoxacin, ketoprofen, erythromycin, naproxen, ibuprofen, diclofenac and enrofloxacin. Similar compounds were reported in rivers in China, indicating a similar usage pattern in both of these developing countries. In a study reported from an open well in southern India, the groundwater showed the presence of cetirizine, ciprofloxacin, enoxacin, citalopram and terbinafine, which was close to a WTP receiving effluents from pharmaceutical production.

Groundwater resource vulnerability and spatial variability of nitrate contamination: Insights from high density tubewell monitoring in a hard rock aquifer.

Agriculture has been increasingly relying on groundwater irrigation for the last decades, leading to severe groundwater depletion and/or nitrate contamination. Understanding the links between nitrate concentration and groundwater resource is a prerequisite for assessing the sustainability of irrigated systems. The Berambadi catchment (ORE-BVET/Kabini Critical Zone Observatory) in Southern India is a typical example of intensive irrigated agriculture and then an ideal site to study the relative influences of land use, management practices and aquifer properties on NO3 spatial distribution in groundwater. The monitoring of >200 tube wells revealed nitrate concentrations from 1 to 360mg/L. Three configurations of groundwater level and elevation gradient were identified: i) NO3 hot spots associated to deep groundwater levels (30-60m) and low groundwater elevation gradient suggest small groundwater reserve with absence of lateral flow, then degradation of groundwater quality due to recycling through pumping and return flow; ii) high groundwater elevation gradient, moderate NO3 concentrations suggest that significant lateral flow prevented NO3 enrichment; iii) low NO3 concentrations, low groundwater elevation gradient and shallow groundwater indicate a large reserve. We propose that mapping groundwater level and gradient could be used to delineate zones vulnerable to agriculture intensification in catchments where groundwater from low-yielding aquifers is the only source of irrigation. Then, wells located in low groundwater elevation gradient zones are likely to be suitable for assessing the impacts of local agricultural systems, while wells located in zones with high elevation gradient would reflect the average groundwater quality of the catchment, and hence should be used for regional mapping of groundwater quality. Irrigation with NO3 concentrated groundwater induces a "hidden" input of nitrogen to the crop which can reach 200kgN/ha/yr in hotspot areas, enhancing groundwater contamination. Such fluxes, once taken into account in fertilizer management, would allow optimizing fertilizer consumption and mitigate high nitrate concentrations in groundwater.

Removal rates of antibiotics in four sewage treatment plants in South India.

The occurrence and removal of seven selected pharmaceutical compounds (PCs) in sewage treatment plants (STPs) in South India were investigated. The PCs selected for this study were sulfamethoxazole (SMX), trimethoprim (TMP), chloramphenicol (CAP), erythromycin (ERY), naproxen (NPX), bezafibrate (BZF), and ampicillin (AMP). Wastewater samples were collected from inlet and outlet of the STPs during pre-monsoon, monsoon, and post-monsoon seasons to investigate the seasonal influences in occurrence and removal rates. The analytical method was based on simultaneous extraction of all target compounds by solid phase extraction (SPE), using a hydrophilic-lipophilic-balanced (HLB) sorbent followed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The STP that catered exclusively to domestic wastewater had lesser concentrations of PCs compared to the STPs serving the combined hospital and domestic effluents. SMX was the dominant compound in all effluents with the highest concentration at 3.2 µg/L in the outlet of an STP. TMP and ERY were the other PCs present at higher concentrations in STP outlets (1 µg/L and 0-0.13 µg/L, respectively). Removal rates varied from 100 % for BZF to 60-100 % for SMX, CTX, and AMP.