PAEs and PBDEs in plastic fragments and wetland sediments in Yangtze estuary.

Phthalates (PAEs) and polybrominated diphenyl ethers (PBDEs) are widely used as additives in various plastic products. Because of their ubiquity and potential hazards to the environment, they have attracted widespread attention. This research supports the addition critical data of the concentration and distribution of PAEs and PBDEs in the plastic fragments and wetland sediments in Yangtze Estuary.

A new method to extract Th, Th and Pa from seawater using a bulk-extraction technique with Nobias PA-1 chelating resin.

The long-lived radioisotopes of Th and Pa are unique tracers for quantifying rates of biogeochemical processes in the ocean. However, their generally low concentrations (sub-fg/kg for Th and Pa and pg/kg for Th) in seawater make them difficult to measure. Here, we present a new approach to determine Th and Th using Nobias PA-1 chelating resin following a bulk-extraction technique, and report for the first time the use of this resin to measure Pa concentrations.

Seven centuries of reconstructed Brahmaputra River discharge demonstrate underestimated high discharge and flood hazard frequency.

The lower Brahmaputra River in Bangladesh and Northeast India often floods during the monsoon season, with catastrophic consequences for people throughout the region. While most climate models predict an intensified monsoon and increase in flood risk with warming, robust baseline estimates of natural climate variability in the basin are limited by the short observational record. Here we use a new seven-century (1309-2004 C.

Molecular and isotopic evidence reveals the end-Triassic carbon isotope excursion is not from massive exogenous light carbon.

The negative organic carbon isotope excursion (CIE) associated with the end-Triassic mass extinction (ETE) is conventionally interpreted as the result of a massive flux of isotopically light carbon from exogenous sources into the atmosphere (e.g., thermogenic methane and/or methane clathrate dissociation linked to the Central Atlantic Magmatic Province [CAMP]).

A circumpolar dust conveyor in the glacial Southern Ocean.

The increased flux of soluble iron (Fe) to the Fe-deficient Southern Ocean by atmospheric dust is considered to have stimulated the net primary production and carbon export, thus promoting atmospheric CO drawdown during glacial periods. Yet, little is known about the sources and transport pathways of Southern Hemisphere dust during the Last Glacial Maximum (LGM). Here we show that Central South America (~24‒32°S) contributed up to ~80% of the dust deposition in the South Pacific Subantarctic Zone via efficient circum-Antarctic dust transport during the LGM, whereas the Antarctic Zone was dominated by dust from Australia.

Early life of Neanderthals.

The early onset of weaning in modern humans has been linked to the high nutritional demand of brain development that is intimately connected with infant physiology and growth rate. In Neanderthals, ontogenetic patterns in early life are still debated, with some studies suggesting an accelerated development and others indicating only subtle differences vs. modern humans.

A Spatially Variable Time Series of Sea Level Change Due to Artificial Water Impoundment.

The artificial impoundment of water behind dams causes global mean sea level (GMSL) to fall as reservoirs fill but also generates a local rise in sea level due to the increased mass in the reservoir and the crustal deformation this mass induces. To estimate spatiotemporal fluctuations in sea level due to water impoundment, we use a historical data set that includes 6,329 reservoirs completed between 1900 and 2011, as well as projections of 3,565 reservoirs that are expected to be completed by 2040. The GMSL change associated with the historical data (-0.

Indian Ocean warming as a driver of the North Atlantic warming hole.

Over the past century, the subpolar North Atlantic experienced slight cooling or suppressed warming, relative to the background positive temperature trends, often dubbed the North Atlantic warming hole (NAWH). The causes of the NAWH remain under debate. Here we conduct coupled ocean-atmosphere simulations to demonstrate that enhanced Indian Ocean warming, another salient feature of global warming, could increase local rainfall and through teleconnections strengthen surface westerly winds south of Greenland, cooling the subpolar North Atlantic.

Effects of dam construction on arsenic mobility and transport in two large rivers in Tibet, China.

Construction of dams on the Singe Tsangpo (ST) and the Yarlung Tsangpo (YT) Rivers, the upper stretch of the Indus and the Brahmaputra Rivers, respectively, are expected to affect material transport. To evaluate the effects of dam construction on arsenic (As) mobility and transport in the ST River and the YT River in Tibet and the downstream river basins, water column and sediment core samples in the Shiquan Reservoir of the ST River and in the Zam Reservoir of the YT River were obtained in August 2017, and January and May 2018, and additionally, at the inflows and outfalls of the reservoirs. The seasonal variation of dissolved As contents in the inflow water of the Zam Reservoir and the Shiquan Reservoir was regulated by the mixing between the low-As river runoff and the high-As hot spring input.

Heterotrophic Carbon Fixation in a Salamander-Alga Symbiosis.

The unique symbiosis between a vertebrate salamander, , and unicellular green alga, , involves multiple modes of interaction. These include an ectosymbiotic interaction where the alga colonizes the egg capsule, and an intracellular interaction where the alga enters tissues and cells of the salamander. One common interaction in mutualist photosymbioses is the transfer of photosynthate from the algal symbiont to the host animal.

Locations of Adolescent Physical Activity in an Urban Environment and Their Associations with Air Pollution and Lung Function.

Physical activity while being exposed to high concentrations of air pollution may lead to greater inhalation of pollutant particles and gases. Thus, owing to features of the built city environment, specific locations where physical activity take place may put individuals at increased risk for harmful inhaled exposures leading to decrements in lung function. The objectives were to determine locations throughout an urban landscape where children engage in moderate to vigorous activity (MVA).

Similar retardation of arsenic in gray Holocene and orange Pleistocene sediments: Evidence from field-based column experiments in Bangladesh.

Groundwater flow has the potential to introduce arsenic (As) in previously uncontaminated aquifers. The extent to which As transport is retarded by adsorption is particularly relevant in Bangladesh where low-As wells offer the best chance of reducing chronic exposure to As of a large rural population dependent on groundwater. In this study, column experiments were conducted with intact cores in the field to measure As retardation.

Environmental impacts of reclaimed asphalt pavement on leaching of metals into groundwater.

To investigate the environmental impacts of reclaimed asphalt pavement (RAP) while it was freshly processed (i.e. hot mixed asphalt or HMA) and after being subjected to weathering, three RAP materials, namely north-RAP, central-RAP, south-RAP, from three plants and one fresh HMA loose mix samples (Fresh-HMA) throughout New Jersey, USA underwent four different weathering processes including: UV and precipitation weathering on unbounded RAP, UV and precipitation weathering on compacted RAP, weathering by heat and moisture cycles, and groundwater flow-through leaching.

The effects of anthropogenic and volcanic aerosols and greenhouse gases on twentieth century Sahel precipitation.

There is little scientific consensus on the importance of external climate forcings-including anthropogenic aerosols, volcanic aerosols, and greenhouse gases (GHG)-relative to each other and to internal variability in dictating past and future Sahel rainfall. We address this query by relating a 3-tiered multi-model mean (MMM) over the Climate Model Intercomparison Project phase 5 "twentieth century" and pre-Industrial control simulations to observations. The comparison of single-forcing and historical simulations highlights the importance of anthropogenic and volcanic aerosols over GHG in generating forced Sahel rainfall variability in models.

Machine Learning Models of Groundwater Arsenic Spatial Distribution in Bangladesh: Influence of Holocene Sediment Depositional History.

Recent advances in machine learning methods offer the opportunity to improve risk assessment and to decipher factors influencing the spatial variability of groundwater arsenic ([As]). A systematic comparison reveals that boosted regression trees (BRT) and random forest (RF) outperform logistic regression. The probability of [As] exceeding 5 μg/L (approximate median value of Bangladesh [As]), 10 μg/L (WHO provisional guideline value), and 50 μg/L (Bangladesh drinking water standard) is modeled by BRT and RF methods for Bangladesh and its four subregions demarcated by major rivers.

Climate impacts of a weakened Atlantic Meridional Overturning Circulation in a warming climate.

While the Atlantic Meridional Overturning Circulation (AMOC) is projected to slow down under anthropogenic warming, the exact role of the AMOC in future climate change has not been fully quantified. Here, we present a method to stabilize the AMOC intensity in anthropogenic warming experiments by removing fresh water from the subpolar North Atlantic. This method enables us to isolate the AMOC climatic impacts in experiments with a full-physics climate model.

Limited and localized magmatism in the Central Atlantic Magmatic Province.

The Central Atlantic Magmatic Province (CAMP) is the most aerially extensive magmatic event in Earth's history, but many questions remain about its origin, volume, and distribution. Despite many observations of CAMP magmatism near Earth's surface, few constraints exist on CAMP intrusions at depth. Here we present detailed constraints on crustal and upper mantle structure from wide-angle seismic data across the Triassic South Georgia Rift that formed shortly before CAMP.

Toxicity of particles emitted by fireworks.

Background: Particle matter (PM) has been associated with increased morbidity and mortality rates across the world. This study was designed to test the hypotheses that pyrotechnic firework displays introduce significant amounts of toxic metals into the atmosphere and are hazardous to human health. Size-selective emissions from 10 different fireworks displays were collected during particle generation in a dynamic, stainless steel chamber and tested for toxicity in cells.

Assessing the sorption of pharmaceuticals to microplastics through in-situ experiments in New York City waterways.

Adsorption of organic pollutants onto microplastics has been reported in prior studies, indicating the potential of these particles to serve as vectors of pollutants. Most prior investigations, however, have been conducted in laboratories under conditions with relatively little environmental relevance. Here we report the results of in-situ experiments to investigate the adsorption of pharmaceuticals (atenolol, sulfamethoxazole, and ibuprofen) on to eight types of test materials (pellets from five types of widely-used polymers, small pieces of straws, fragments of bags, and glass beads for control).

Sequential extraction procedure to obtain the composition of terrigenous detritus in marine sediments.

The geochemical and isotopic composition of terrigenous clays from marine sediments can provide important information on the sources and pathways of sediments. In order to extract the detrital signal from bulk marine sediments, standard sediment leaching methods are commonly applied to remove carbonate and ferromanganese oxides. In comparison to most previous studies that aimed to extract the terrestrial signal from marine sediments we additionally applied a CsCl wash throughout the sample preparation Simon et al.

Arsenic contamination of Bangladesh aquifers exacerbated by clay layers.

Confining clay layers typically protect groundwater aquifers against downward intrusion of contaminants. In the context of groundwater arsenic in Bangladesh, we challenge this notion here by showing that organic carbon drawn from a clay layer into a low-arsenic pre-Holocene (>12 kyr-old) aquifer promotes the reductive dissolution of iron oxides and the release of arsenic. The finding explains a steady rise in arsenic concentrations in a pre-Holocene aquifer below such a clay layer and the repeated failure of a structurally sound community well.

Opening a Large Delivery Service Warehouse in the South Bronx: Impacts on Traffic, Air Pollution, and Noise.

Mott Haven, a low-income neighborhood in New York City, suffers from increased air pollution and accommodates several industrial facilities and interstates. In 2018, a large delivery service warehouse opened. Our objectives are to characterize black carbon (BC), fine particulate matter (PM), and noise in the community; model changes in traffic due to the facility opening; and estimate associated BC and noise changes.

Inferring Changes in Summertime Surface Ozone-NO-VOC Chemistry over U.S. Urban Areas from Two Decades of Satellite and Ground-Based Observations.

Urban ozone (O) formation can be limited by NO, VOCs, or both, complicating the design of effective O abatement plans. A satellite-retrieved ratio of formaldehyde to NO (HCHO/NO), developed from theory and modeling, has previously been used to indicate O formation chemistry. Here, we connect this space-based indicator to spatiotemporal variations in O recorded by on-the-ground monitors over major U.