Pollen allergy risk is modified by air pollutants, including ozone, but the chemical modifications induced on pollen grains are poorly understood. Pollen lipidic extract has been shown to act as an adjuvant to the allergenic reaction and therefore, the modification of lipids by air pollutants could have health implications. Birch pollen was exposed in vitro to ozone to explore the reactivity of O₃ on its surface and on its lipidic fraction. Uptake coefficients of ozone were determined for ozone concentration of 117 ppb on the surface of native birch pollen (8.6 ± 0.8 × 10⁻⁶), defatted pollen (9.9 ± 0.9 × 10⁻⁶), and for crushed pollen grains (34±3 × 10⁻⁶). The mass of ozone uptaken was increased by a factor of four for crushed pollen compared to native pollen showing a higher susceptibility to ozone of cytoplasmic granules and broken pollen grains. A total mass of extractible lipids of 27 mg per gram of birch pollen was found and a fraction of these lipids was identified and quantified (fatty acids, alkanes, alkenes and aldehydes). The distribution of lipids was modified by ozone exposure of 115 and 1000 ppb for 16 h with the following reactivity: consumption of alkene, formation of aldehydes and formation of nonanoic acid and octadecanoic acid. The quantity of ozone trapped in the lipidic fraction during 15 min at 115 ppb is enough to contribute to the reactivity of one-third of the alkenes demonstrating that pollen could be susceptible to an atmospheric increase of ozone concentration even for a very short duration complicating the understanding of the link between pollen allergy and pollution.

Genotoxic compounds, as common contaminants of the air environment, are of interest in air pollution monitoring. There are several methods to determine the level of these contaminants in different localities, many of which may be difficult to access with the use of conventional active and passive samplers. In the present study, the needles Pinus mugo Turra and Picea abies were used to monitor sampling localities in Austria, Slovakia, and the Czech Republic. Needles were extracted and chemical analysis and the genotoxicity bioassay SOS chromotest were used to obtain complex information about the chemical mixture of pollutants present and their genotoxic effects. The SOS chromotest method was optimized by using a CPRG chromogenic substrate to reduce the false positive genotoxic effect of needle extracts. Pinus mugo Turra and Picea abies were identified as suitable passive sampling matrices for long-term air monitoring using the same plants sampled at the same time. The presented study brings an innovative method for the fast screening and identification of localities loaded by genotoxic active air contaminants.

High arsenic groundwater generally coexists with elevated Fe2+ concentrations (mg L−1 levels) under reducing conditions, but an explanation for the extremely high arsenic (up to ∼2690) concentrations at very low Fe2+ (i.e., μg L−1 levels) in groundwater of Datong Basin remains elusive. Field groundwater investigation and laboratory microcosm experiments were implemented in this study. The field groundwater was characterized by weakly alkaline (pH 7.69 to 8.34) and reducing conditions (Eh −221.7 to −31.9 mV) and arsenic concentration averages at 697 μg L−1. Acinetobacter (5.9–51.3%), Desulfosporosinus (4.6–30.2%), Brevundimonas (3.9–19%) and Pseudomonas (3.2–14.6%) were identified as the dominant genera in the bacterial communities. Bacterially mediated arsenate reduction, Fe(III) reduction, and sulfate reduction are processes occurring (or having previously occurred) in the groundwater. Results from incubation experiment (27 d) revealed that nitrate, arsenate, and Fe(III)/sulfate reduced sequentially with time under anoxic conditions, while Fe(III) and sulfate reduction processes had no obvious differences, occurring almost simultaneously. Moreover, low Fe2+ concentrations were attributed to initially high pH conditions, which relatively retarded Fe(III) reduction. In addition, arsenic behavior in relation to groundwater redox conditions, matrices, and solution chemistry were elaborated. Bacterial arsenate reduction process proceeded before Fe(III) and sulfate reduction in the incubation experiment, and the total arsenic concentration (dominated by arsenite) gradually increased from ∼7 to 115 μg L−1 as arsenate was reduced. Accordingly, bacterially mediated reductive desorption of arsenate is identified as the main process controlling arsenic mobility, while Fe(III) reduction coupled with sulfate reduction are secondary processes that have also contributed to arsenic enrichment in the study site. Overall, this study provide important insights into the mechanism controlling arsenic mobility under weakly alkaline and reducing conditions, and furnishes that arsenate reduction by bacteria play a major role leading to high accumulation of desorbed arsenite in groundwater.

Assessing the toxicity posed by mixtures of unknown chemicals to aquatic organisms is challenging. In this study, water samples from six cross-sections along the Xitiaoxi River Basin (XRB) were monthly or bimonthly collected in 2014. The year-period physiochemical parameters as well as one-month-water sample based acute biotoxicity tests showed that the river water quality of the year was generally in a good status. High performance liquid chromatography (HPLC) screening based on one-month-water samples suggested that the organic pollutants might be non-to-moderately-polar chemicals in very low concentrations. One-month-water sample based RNA-seq was performed to measure the mRNA differential expression profile of zebrafish larvae to furtherly explore the potential bioeffect and the spatial water quality change of the river. Result indicated that the number of deferentially expressed genes (DEGs) tended to increase along the downstream direction of the river. Gene ontology (GO) enrichment analysis implied that the key pollutants might mainly be the function disruptors of biological processes. Principle components analysis (PCA) combining with transcripts and one-month-water sample based physiochemical parameters indicated that the pollution might be similar at TP, DP and CTB sites while pollution homology existed on some extent between YBQ and JW sites. Although the water quality of the river had a complex time-space alternation during the year, and the one-month-data based RNA-seq could not reflex the whole year-water quality of a watershed, the gene expression profile via RNA-seq provided an alternative way for assessing integrated biotoxicity of surface water, and it was relatively fit for early-warning of water quality of a watershed with unobservable acute toxicity. However, the identification of detail toxicants and the links between DEGs and pollution level as well as physiological-biochemical toxicity needed further investigation.

China is now experiencing major public health challenges caused by air pollution. Few studies have quantified the dynamics of air pollution and its impact on the risk of respiratory infection. We conducted an integrated data analysis to quantify the association among air quality index (AQI), meteorological variables and respiratory infection risk in Shaanxi province of China in the period of November 15th, 2010 to November 14th, 2016. Our analysis illustrated a statistically significantly positive correlation between the number of influenza-like illness (ILI) cases and AQI, and the respiratory infection risk has increased progressively with increased AQI with a time lag of 0–3 days. We also developed mathematical models for the AQI trend and respiratory infection dynamics, incorporating AQI-dependent incidence and AQI-based behaviour change interventions. Our combined data and modelling analysis estimated the basic reproduction number for the respiratory infection during the studying period to be 2.4076, higher than the basic reproduction number of the 2009 pandemic influenza in the same province. Our modelling-based simulations concluded that, in terms of respiratory infection risk reduction, the persistent control of emission in the China's blue-sky programme is much more effective than substantial social-economic interventions implemented only during the smog days.

During the 20th century the impacts of industrialization and urbanization in Galveston Bay resulted in significant shifts in trace metals (Hg, Pb, Ni, Zn) and vascular plant biomarkers (lignin phenols) recorded within the surface sediments and sediment cores profile. A total of 22 sediment cores were collected in Galveston Bay in order to reconstruct the historical input of Hg, Pb, Ni, Zn and terrestrial organic matter. Total Hg (T-Hg) concentration ranged between 6 and 162 ng g−1 in surface sediments, and showed decreasing concentrations southward from the Houston Ship Channel (HSC) toward the open estuary. Core profiles of T-Hg and trace metals (Ni, Zn) showed substantial inputs starting in 1905, with peak concentrations between 1960 and 1970's, and decreasing thereafter with exception to Pb, which peaked around 1930–1940s. Stable carbon isotopes and lignin phenols showed an increasing input of terrestrial organic matter driven by urban development within the watershed in the early 1940s. Both the enrichment factor and the geoaccumulation index (Igeo) for T-Hg as a measure of the effectiveness of environmental management practices showed substantial improvements since the 1970s. The natural recovery rate in Galveston Bay since the peak input of T-Hg was non-linear and displayed a slow recovery during the twenty-first century.

Shallow aquifers are the most accessible reservoirs of potable groundwater; nevertheless, they are also prone to various sources of pollution and it is usually difficult to distinguish between human and natural sources at the watershed scale. The area chosen for this study (the Campania Plain) is characterized by high spatial heterogeneities both in geochemical features and in hydraulic properties. Groundwater mineralization is driven by many processes such as, geothermal activity, weathering of volcanic products and intense human activities. In such a landscape, multivariate statistical analysis has been used to differentiate among the main hydrochemical processes occurring in the area, using three different approaches of factor analysis: (i) major elements, (ii) trace elements, (iii) both major and trace elements. The elaboration of the factor analysis approaches has revealed seven distinct hydrogeochemical processes: i) Salinization (Cl⁻, Na⁺); ii) Carbonate rocks dissolution; iii) Anthropogenic inputs (NO₃⁻, SO₄²⁻, U, V); iv) Reducing conditions (Fe²⁺, Mn²⁺); v) Heavy metals contamination (Cr and Ni); vi) Geothermal fluids influence (Li⁺); and vii) Volcanic products contribution (As, Rb). Results from this study highlight the need to separately apply factor analysis when a large data set of trace elements is available. In fact, the impact of geothermal fluids in the shallow aquifer was identified from the application of the factor analysis using only trace elements. This study also reveals that the factor analysis of major and trace elements can differentiate between anthropogenic and geogenic sources of pollution in intensively exploited aquifers.

The widespread cultivation of transgenic Bt cotton makes assessing the potential effects of this recombinant crop on non-target organisms a priority. However, the effect of Bt cotton on many insects is currently virtually unknown. The plant bug Adelphocoris suturalis is now a major pest of cotton in southern China and the beetle Haptoncus luteolus is one of the most ancient cotton pollinators. We conducted laboratory experiments to evaluate the toxicity of the Bt cotton varieties ZMSJ, which expresses the toxins Cry1Ac and Cry2Ab, and ZMKCKC, which expresses Cry1Ac and EPSPS, on adult A. suturalis and H. luteolus. No significant increase in the mortality of either species was detected after feeding on Bt cotton leaves or pollen for 7 days. Trace amounts of Cry1Ac and Cry2Ab proteins could be detected in both species but in vitro binding experiments found no evidence of Cry1Ac and Cry2Ab binding proteins. These results demonstrate that feeding on the leaves or pollen of these two Bt cotton varieties has no toxic effects on adult A. suturalis or H. luteolus.