Geostatistical model of the spatial distribution of arsenic in groundwaters in Gujarat State, India

From Springer Nature via Jisc Publications RouterHistory: received 2019-12-15, accepted 2020-06-24, registration 2020-06-24, pub-electronic 2020-07-11, online 2020-07-11, pub-print 2021-07Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; doi: http://dx.doi.org/10.13039/501100000266; Grant(s): IAA Impact AwardAbstract: Geogenic arsenic contamination in groundwaters poses a severe health risk to hundreds of millions of people globally. Notwithstanding the particular risks to exposed populations in the Indian sub-continent, at the time of writing, there was a paucity of geostatistically based models of the spatial distribution of groundwater hazard in India. In this study, we used logistic regression models of secondary groundwater arsenic data with research-informed secondary soil, climate and topographic variables as principal predictors generate hazard and risk maps of groundwater arsenic at a resolution of 1 km across Gujarat State. By combining models based on different arsenic concentrations, we have generated a pseudo-contour map of groundwater arsenic concentrations, which indicates greater arsenic hazard (> 10 μg/L) in the northwest, northeast and south-east parts of Kachchh District as well as northwest and southwest Banas Kantha District. The total number of people living in areas in Gujarat with groundwater arsenic concentration exceeding 10 μg/L is estimated to be around 122,000, of which we estimate approximately 49,000 people consume groundwater exceeding 10 µg/L. Using simple previously published dose–response relationships, this is estimated to have given rise to 700 (prevalence) cases of skin cancer and around 10 cases of premature avoidable mortality/annum from internal (lung, liver, bladder) cancers—that latter value is on the order of just 0.001% of internal cancers in Gujarat, reflecting the relative low groundwater arsenic hazard in Gujarat State

A global perspective on assessing groundwater quality

An assessment of global groundwater quality is needed in response to the threats posed by anthropogenic and geogenic contaminants. This essay summarises the challenges involved, including a large number of potentially relevant water quality parameters, the poor availability of data in many regions and the complex nature of groundwater systems. Direct monitoring data can sometimes be augmented by indirect methods such as earth observations, and by involving citizen science. A new web portal is being developed to complement existing databases

Joint inversions of three types of electromagnetic data explicitly constrained by seismic observations: results from the central Okavango Delta, Botswana

The Okavango Delta of northern Botswana is one of the world's largest inland deltas or megafans. To obtain information on the character of sediments and basement depths, audiomagnetotelluric (AMT), controlled-source audiomagnetotelluric (CSAMT) and central-loop transient electromagnetic (TEM) data were collected on the largest island within the delta. The data were inverted individually and jointly for 1-D models of electric resistivity. Distortion effects in the AMT and CSAMT data were accounted for by including galvanic distortion tensors as free parameters in the inversions. By employing Marquardt-Levenberg inversion, we found that a 3-layer model comprising a resistive layer overlying sequentially a conductive layer and a deeper resistive layer was sufficient to explain all of the electromagnetic data. However, the top of the basal resistive layer from electromagnetic-only inversions was much shallower than the well-determined basement depth observed in high-quality seismic reflection images and seismic refraction velocity tomograms. To resolve this discrepancy, we jointly inverted the electromagnetic data for 4-layer models by including seismic depths to an interface between sedimentary units and to basement as explicit a priori constraints. We have also estimated the interconnected porosities, clay contents and pore-fluid resistivities of the sedimentary units from their electrical resistivities and seismic P-wave velocities using appropriate petrophysical models. In the interpretation of our preferred model, a shallow∼40 m thick freshwater sandy aquifer with 85-100 Ωm resistivity, 10-32 per cent interconnected porosity and <13 per cent clay content overlies a 105-115m thick conductive sequence of clay and intercalated salt-water-saturated sands with 15-20 Ωm total resistivity, 1−27 per cent interconnected porosity and 15-60 per cent clay content. A third∼60 m thick sandy layer with 40-50 Ωm resistivity, 10-33 per cent interconnected porosity and <15 per cent clay content is underlain by the basement with 3200-4000 Ωm total resistivity. According to an interpretation of helicopter TEM data that cover the entire Okavango Delta and borehole logs, the second and third layers may represent lacustrine sediments from Paleo Lake Makgadikgadi and a moderately resistive freshwater aquifer comprising sediments of the recently proposed Paleo Okavango Megafan, respectivel

Gaseous and soil OCPs and PCBs along the Indus River, Pakistan: spatial patterns and air–soil gradients

This study presents first-hand information on the occurrence of persistent organic pollutants (POPs) in the ambient air and surface soil along the Indus flood-plain, Pakistan. The sampling campaign was conducted at 15 site locations during 2014–15, along the Indus River (approximately 1300 km). Composite surface soil samples (N = 15) and passive air samples (N = 15) were collected for the estimation of gaseous POPs as well as air–soil exchange to evaluate the POP emission and distribution or dispersion patterns, source tracking, and contribution of the local and regional sources towards POP accumulation in the Indus River system. Among the studied POPs, levels of DDTs and PCBs were noticeably higher in ambient air (50–560 and 10–1100 pg m−3) and in soil (0.20–350 and 1.40–20 ng g−1), respectively. Regarding the spatial patterns, higher DDT concentrations (ng g−1) were detected in the air and soil samples collected from the wet mountain zone (WMZ) (p \u3c 0.05), followed by the alluvial riverine zone (ARZ), low-lying mountain zone (LLZ), and frozen mountain zone (FMZ). The PCB data did not exhibit significant differences (p \u3e 0.05) for the air samples, while PCB concentrations were significantly higher (p \u3c 0.05) in soil from the LLZ, which may be associated with rapid urbanization and industrial activities in this area. The air–soil exchange of DDTs and PCBs showed net volatilization at most of the studied sites except for a few samples from the FMZ and WMZ. Results of this study about air–soil exchange gradients indicate the long range regional atmospheric transport (LRAT) of POPs to the colder areas (FMZ) of Pakistan, where these act as a secondary source of POPs in these areas

Freely dissolved Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs) along the Indus River Pakistan: Spatial pattern and Risk assessment

Freely dissolved OCPs and PCBs were measured by using polyethylene passive samplers at 15 sites during 2014 throughout the stretch of the Indus River to investigate the spatial pattern and risk assess. Levels (pg/L) of dissolved ∑OCPs and ∑PCBs ranged from 34 to 1600 and from 3 to 230. Among the detected OCPs, dissolved DDTs (p,p′-DDE, followed by p,p′-DDT) predominated with levels of 0.48 to 220 pg/L. The order of occurrence for other studied OCPs was as follows: HCB, endosulfans, chlordanes, and HCHs. Spatially, dissolved (pg/L) ∑OCPs varied (p \u3c 0.05) as the following: surface water of the alluvial riverine zone (ARZ) showed the highest levels (114) followed by the frozen mountain zone (FMZ) (52.9), low-lying zone (LLZ) (28.73), and wet mountain zone (WMZ) (14.43), respectively. However, our zone-wise PCB data did not exhibit significant differences (p \u3e 0.05). Principal component analysis/multilinear regression results showed pesticide usage in the crop/orchard fields and health sector, electric and electronic materials, and widespread industrial activities as the main source of OCPs and PCBs along the Indus River. Our results showed that OCPs and PCBs contaminated water intake, playing an important role towards the considerable cancer/non-cancer risk (HI and CR values) along the Indus River Flood-Plain

The Grizzly, April 21, 1997

Dr. Martha Groom to Speak on Communities and Ecosystems • Summer Research Fellows Announced • Housing Changes • Debate on Quality of Majors • Opinion: To Students With Constructive Criticism, Write On!; One\u27s Right to Life and Death; Membership has its Privileges; Operation Understanding; More Money = Better Education? • Final Exam Schedule • Collegeville Headstart Benefits from Bears Game Haircuts • Softball Sweeps Western Maryland • Women\u27s Lacrosse Wins Two in Conference • Baseball Swept • Golf Team Sets New Course Records • Women\u27s Tennis at 3-3https://digitalcommons.ursinus.edu/grizzlynews/1403/thumbnail.jp

The Grizzly, November 18, 1996

Bears Beat Dickinson, Make NCAA Playoffs • Security and RLO Work Through Changes • Opinion: Question of Security; An Insider Throwing out a Line; One of Four Seasons; It\u27s All in Your Head • Concert and Jazz Bands to Perform • Jude: Hardy\u27s Novel Arrives in the Flesh • Bears Win Conference Championship To Make NCAA Playoffs!!! • Getz and Finnegan Receive Post-Season Honorshttps://digitalcommons.ursinus.edu/grizzlynews/1392/thumbnail.jp

The Grizzly, November 25, 1996

Honors Pilot Program a Success • Pass-Fail Forum Set for Dec. 4 • Opinion: What About Easter?; It Hurts; Jesus is Dead?; Thanksgiving; Is Ursinus a Disposable Society?; Never-Never Land • Final Exam Schedule • Bears Suffer 31-24 Defeat in NCAA Playoffs • Men\u27s Basketball Opens with an Overtime Win • Bears Place Nine On All-Conference Team • Wrestling Opens with Two Winshttps://digitalcommons.ursinus.edu/grizzlynews/1393/thumbnail.jp

The Grizzly, November 4, 1996

Berman Exhibit Focuses on the Environment • Chemist Speaks on Authentication Processes • Dr. Borsdorf Lauded • Opinion: Future of America; Are we too Dependent on Computers?; Questions on Openness? • This Wednesday is Unity Day! • Shepherdson\u27s TD Run Lifts Ursinus Over Muhls • Men\u27s Soccer Loses Heartbreaker to Western Maryland • Field Hockey Loses Eighth Straight • Larkin Named Player of the Weekhttps://digitalcommons.ursinus.edu/grizzlynews/1390/thumbnail.jp

The Grizzly, April 14, 1997

Student Art Collection to be Exhibited at Berman Museum • Author Lee Gutkind Speaks • Ursinus Jazz Ensemble Performs • Opinion: Ursinus Needs a Foreign Revolution; Common Sense; Let\u27s Get Things Nice and Clear • Letter: Thanks to Volunteers • Shakespeare\u27s Two Noble Kinsmen Visit Ursinus • College Choir to Perform Sacred Service • Right On, My Sister! • Women\u27s Lacrosse Deals Rowan a Defeat • Guenther Named New Football Coach • Women\u27s Tennis Team Transformed • Haverford Pounds Bears • Men\u27s Tennis Falls to Widener • Softball Team Drops Eight of Last Ninehttps://digitalcommons.ursinus.edu/grizzlynews/1402/thumbnail.jp