Reduction of particulate matter (PM) has emerged as one of the most significant challenges in public health and environment protection worldwide. To address PM-related problems and effectively remove fine particulate matter (PM2.5), environmentalists proposed tree planting and afforestation as eco-friendly strategies. However, the PM removal effect of plants and its primary mechanism remains uncertain. In this study, we experimentally investigated the PM removal performance of five plant species in a closed chamber and the effects of relative humidity (RH) caused by plant evapotranspiration, as a governing parameter. On the basis of the PM removal test for various plant species, we selected Epipremnum aureum (Scindapsus) as a representative plant to identify the PM removal efficiency depending on evapotranspiration and particle type. Results showed that Scindapsus yielded a high PM removal efficiency for smoke type PM2.5 under active transpiration. We examined the correlation of PM removal and relative humidity (RH) and evaluated the increased effect of RH on PM2.5 removal by using a plant-inspired in vitro model. Based on the present results, the increase of RH due to evapotranspiration is crucial to the reduction of PM2.5 using plants.

Toxocariasis is a neglected tropical disease of humans. Although many studies have indicated or shown that environmental contamination with Toxocara species eggs is a major risk factor for toxocariasis in humans, there has been no comprehensive analysis of published data or information. Here, we conducted the first systematic review and meta-analysis of current literature to assess the global prevalence of Toxocara eggs in public places (including beaches, parks and playgrounds). We conducted searches of the PubMed, Embase, Scopus and Science Direct databases for relevant studies published until 20 April 2018, and assessed the prevalence rates of Toxocara eggs in public places. We used the random effects model to calculate pooled prevalence estimates, with 95% confidence intervals (CIs), and analysed data in relation to WHO geographical regions. Subgroup analysis and meta-regressions regarding the geographical and environmental variables were also performed. Of 2384 publications identified, 109 studies that tested 42,797 soil samples in 40 countries were included in the meta-analysis. The pooled global prevalence of Toxocara eggs in public places was 21% (95% CI, 16–27%; 13,895/42,797). The estimated prevalence rates in the different WHO regions ranged from 13% to 35%: Western Pacific (35%; 95% CI, 15–58%), Africa (27%; 95% CI, 11–47%), South America (25%; 95% CI, 13–33%), South-East Asia (21%; 95% CI, 3–49%), Middle East and North Africa (18%; 95% CI, 11–24%), Europe (18%; 95% CI, 14–22%), and North and Central Americas (13%; 95% CI, 8–23%). A high prevalence was significantly associated with high geographical longitude (P = 0.04), low latitude (P = 0.02) and high relative environmental humidity (P = 0.04). This meta-analysis of data from published records indicates that public places are often heavily contaminated with eggs of Toxocara. This finding calls for measures to reduce the potential risk of infection and disease in humans.

The impact of ambient air pollution on pregnant women is a concern in China. However, little is known about the association between air pollution and preeclampsia and the potential modifying effects of meteorological conditions have not been assessed. This study aimed to assess the effects of prenatal exposure to air pollution on preeclampsia, and to explore whether temperature and humidity modify the effects. We performed a retrospective cohort study based on 1.21 million singleton births from the birth registration system in Shenzhen, China, between 2005 and 2012. Daily average measurements of particulate matter <10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), air temperature (T), and dew point (Td) were collected. Logistic regression models were performed to estimate associations between air pollution and preeclampsia during the first and second trimesters, and during the entire pregnancy. In each time window, we observed a positive gradient of increasing preeclampsia risk with increasing quartiles of PM10 and SO2 exposure. When stratified by T and Td in three categories (<5th, 5th −95th, and >95th percentile), we found a significant interaction between PM10 and Td on preeclampsia; the adverse effects of PM10 increased with Td. During the entire pregnancy, there was a null association between PM10 and preeclampsia under Td < 5th percentile. Preeclampsia risk increased by 23% (95% CI: 19–26%) when 5th < Td < 95th percentile, and by 34% (16–55%) when Td > 95th percentile. We also found that air pollution effects on preeclampsia in autumn/winter seasons were stronger than those in the spring/summer. This is the first study to address modifying effects of meteorological factors on the association between air pollution and preeclampsia. Findings indicate that prenatal exposure to PM10 and SO2 increase preeclampsia risk in Shenzhen, China, and the effects could be modified by humidity. Pregnant women should limit air pollution exposure, particularly during humid periods.

The prevalence of allergic diseases has increased in the past few decades. Bio-aerosol proteins and their chemical modifications, such as 3-nitrotyrosine (3-NT), in the atmosphere have been attracting attention due to their promotive effects on allergies. 3-NT is generated from the amino acid, tyrosine, through a reaction with ozone (O3) and nitrogen dioxide (NO2). However, the underlying mechanisms have not yet been elucidated in detail. Therefore, we measured 3-NT and evaluated the relationships among 3-NT and various pollutants such as sulfur dioxide (SO2), NOx (NO + NO2), ozone (O3), PM7, total suspended particulate matter (TSP) containing proteins, humidity, and temperature. 3-NT positively correlated with O3, SO2, humidity, and temperature, and negatively correlated with NOx. A multiple regression analysis showed that 3-NT positively associated with O3, humidity, and PM7. O3 positively associated with 3-NT and PM7, and negatively associated with NOx and humidity. These results suggest that 3-NT is generated from PM proteins through a reaction with O3 under high humidity conditions, and that the measurement of 3-NT is important and useful for the research of O3.

To protect ecosystems and their services, the critical load concept has been implemented under the framework of the Convention on Long-range Transboundary Air Pollution (UNECE) to develop effects-oriented air pollution abatement strategies. Critical loads are thresholds below which damaging effects on sensitive habitats do not occur according to current knowledge. Here we use change-point models applied in a Bayesian context to overcome some of the difficulties when estimating empirical critical loads for nitrogen (N) from empirical data. We tested the method using simulated data with varying sample sizes, varying effects of confounding variables, and with varying negative effects of N deposition on species richness. The method was applied to the national-scale plant species richness data from mountain hay meadows and (sub)alpine scrubs sites in Switzerland. Seven confounding factors (elevation, inclination, precipitation, calcareous content, aspect as well as indicator values for humidity and light) were selected based on earlier studies examining numerous environmental factors to explain Swiss vascular plant diversity. The estimated critical load confirmed the existing empirical critical load of 5–15 kg N ha−1 yr−1 for (sub)alpine scrubs, while for mountain hay meadows the estimated critical load was at the lower end of the current empirical critical load range. Based on these results, we suggest to narrow down the critical load range for mountain hay meadows to 10–15 kg N ha−1 yr−1.

Polycyclic aromatic hydrocarbons (PAHs) in suspended particulate matter (SPM) contribute significantly to health risk. Our objectives were to assess the size distribution and sources of 26 PAHs and 11 polycyclic aromatic compounds (PACs) in SPM in the suburban area, Shanghai city, China. Air sampling was carried out on the rooftop of a five-stories building in the campus of Shanghai University. An Andersen high-volume air sampler was employed to collect ambient size-segregated particles from August to September 2015. The toxic particulate PAHs were determined by the gas chromatography mass spectrometry. The concentrations of total PAHs (TPAHs) in SPM and PM1.1 (suspended particulate matter below 1.1 μm) were in the ranges of 4.58–14.5 ng m−3 and 1.82–8.56 ng m−3, respectively. 1,8-naphthalic anhydride showed the highest concentrations among 37 species of PAHs and PACs ranging 7.76–47.9 ng m−3 and 1.50–17.6 ng m−3 in SPM and PM1.1, respectively. The concentrations of high molecular weight 5–6 ring PAHs followed a nearly unimodal size distribution with the highest peak in PM1.1, while other lower molecular weight PAHs were not dependent on particle sizes. The toxicity analysis indicated that the carcinogenic potency of particulate PAHs primarily existed in PM1.1. Regarding meteorological parameters and other pollutants, the positive effect of humidity and NO2 over PAHs was confirmed. Diagnostic ration indicated that the particulate PAHs in Shanghai were mainly derived from motor-vehicle or petroleum combustion. The highest benzo[a]pyrene equivalent (BaPeq) in SPM and PM1.1 were 2.15 ng m−3 and 1.43 ng m−3 calculated by the toxicity equivalency factor, and 69.31 ng m−3 and 47.81 ng m−3 estimated by the potency equivalency factors, respectively. The highest contributors in the total carcinogenicity of the particulate PAHs were dibenzo[a,h]pyrene (46.2% and 45.0%) and benz[j]aceanthrylene (80.2% and 83.1%), respectively while benzo[a]pyrene is lower contributor than other carcinogenic PAHs.

Ozone and energy fluxes have been measured using the eddy covariance technique, from June to December 2004 in Castelporziano near Rome (Italy), and compared to similar measurements made in the previous year. The studied ecosystem consisted in a typical Mediterranean Holm oak forest. Stomatal fluxes have been calculated using the resistance analogy and by inverting the Penmann-Monteith equation. Results showed that the average stomatal contribution accounts for 42.6% of the total fluxes. Non-stomatal deposition proved to be enhanced by increasing leaf wetness and air humidity during the autumnal months. From a comparison of the two years, it can be inferred that water supply is the most important limiting factor for ozone uptake and that prolonged droughts alter significantly the stomatal conductance, even 2 months after the soil water content is replenished. Ozone exposure, expressed as AOT40, behaves similarly to the cumulated stomatal flux in dry conditions whereas a different behaviour for the two indices appears in wet autumnal conditions. A difference also occurs between the two years. Ozone fluxes to a Holm oak coastal forest show inter-annual variations depending on meteorological conditions and water availability.

The Arabian or Persian Gulf is recognized as one of the warmest estuaries globally. The sea surface temperature (SST) has been utilized in several studies to gauge the global warming associated with climate change. In the current investigation we present detailed in situ SST measurements for five consecutive years (2016, 2017, 2018, 2019, 2020) in the northwest of the Gulf, specifically in Kuwait Bay. Results of data analyses were compared with the historical records for the region, revealing that the SST reached an extreme level never previously recorded either in the Gulf. The extreme SST in Kuwait Bay reached 37.6 °C, recorded by the offshore station KISR01 located in the middle of the Bay. The event was associated with heatwave, neap tides, and an extended period of Kous winds which are characterized by high humidity levels and accompanied by large-scale intermittent fish kill incidents that extended the full length of the Kuwait coastline. Several fish kill incidents were reported also at the northern edge of the Gulf along Shatt Al Arab stretch in Iraq. The species found dead during the incident varied considerably, unlike those found in the frequent summer incidents. The records presented in this study may provide evidence to the effects of global warming, aid further research, and encourage the concerned international government bodies to deliver urgent environmental policies.

Samplers made with different materials were tested for the quantitative collection and recovery of mercury halides from the atmospheric air. The tested adsorbent materials included zirconia (ZrO2), titania (TiO2), melted SiO2 (quartz wool) and potassium chloride (KCl). Different processes affecting the sampler efficiency were investigated specifically: breakthrough during sampling because of the surface passivation and loss of already collected mercury halides due to spontaneous reduction or due to the reaction with ozone. Reduction of mercury because of reaction with the atmospheric ozone appeared to be the major cause of the sample loss and it was inherent in all tested materials at a comparable extent. We hypothesized the zirconia layer covered on a ceramic substrate (patented) to be less sensitive to the ozone-caused reduction, inert to gaseous elemental mercury and completely insensitive to atmospheric humidity. In addition, zirconia samplers were highly resistant to heating and they could be used for multiple adsorption/desorption cycles avoiding degradation in the atmospheric air. Key results of the zirconia sampler tests with mercury halides were: the collection efficiency of >98%; reduction with 50 ppb ozone in the first 4 min of exposition to the atmospheric air ─ 6% ±1%; spontaneous reduction at 50 °C in the first 4 min after spiking ─ <0.6%. Along with the above experimental results, some insights into the possible mechanism of interaction of ozone with mercury halides have been provided.

We examined the associations between the daily variations of air pollutants and mortality in the population of İstanbul, Turkey, using generalized linear models while controlling for time trends and meteorological factors over a 6-year period (2007–2012) at different time lags (0–10 days). Effects of the pollutants (Relative Risk (RR) on current-day (lag 0) mortality to the first ten days (lag 10) were determined. Data on daily mortality, daily mean concentrations of air pollutants of PM10, SO2 and NO2 and daily mean concentrations of temperature and humidity for İstanbul were used in the study. We found significant associations between air pollution and daily mortality from cardiovascular disease, respiratory diseases, and total non-accidental causes in İstanbul. An increase of 10 μg/m3 in concentrations of PM10, SO2 and NO2 over 10 days of lag corresponds to RR = 1.0222 (95% Confidence Interval (CI) = 0.9957–1.0494), RR = 1.1639 (95% CI = 1.0279–1.3177) and RR = 1.0327 (95% CI = 1.0105–1.0554) increase of cardiovascular mortality, respectively. The associations for total non-accidental and respiratory mortality were also positive. Among the three air pollutants, SO2 was associated with the largest RR for deaths from cardiovascular disease, respiratory disease and total mortality. In conclusion, our study showed that short-term exposure to air pollution was associated with increased cardiovascular, respiratory and total non-accidental mortality in the city during 2007–2012. These findings may have implications for local environmental and social policies.