Low Particulate Matter Levels Research Articles

Effect modification of air pollution on the association between heat and mortality in five European countries

BackgroundEvidence suggests that air pollution modifies the association between heat and mortality. However, most studies have been conducted in cities without rural data. This time-series study examined potential effect modification of particulate matter (PM) and ozone (O3) on heat-related mortality using small-area data from five European countries, and explored the influence of area characteristics. MethodsWe obtained daily non-accidental death counts from both urban and rural areas in Norway, England and Wales, Germany, Italy, and the Attica region of Greece during the warm season (2000–2018). Daily mean temperatures and air pollutant concentrations were estimated by spatial-temporal models. Heat effect modification by air pollution was assessed in each small area by over-dispersed Poisson regression models with a tensor smoother between temperature and air pollution. We extracted temperature-mortality relationships at the 5th (low), 50th (medium), and 95th (high) percentiles of pollutant distributions. At each air pollution level, we estimated heat-related mortality for a temperature increase from the 75th to the 99th percentile. We applied random-effects meta-analysis to derive the country-specific and overall associations, and mixed-effects meta-regression to examine the influence of urban-rural and coastal typologies and greenness on the heat effect modification by air pollution. ResultsHeat-related mortality risks increased with higher PM levels, rising by 6.4% (95% CI: −2.0%–15.7%), 10.7% (2.6%–19.5%), and 14.1% (4.4%–24.6%) at low, medium, and high PM levels, respectively. This effect modification was consistent in urban and rural regions but more pronounced in non-coastal regions. In addition, heat-mortality associations were slightly stronger at high O3 levels, particularly in regions with low greenness. ConclusionOur analyses of both urban and rural data indicate that air pollution may intensify heat-related mortality, particularly in non-coastal and less green regions. The synergistic effect of heat and air pollution implies a potential pathway of reducing heat-related health impacts by improving air quality.

Prenatal and postnatal early life exposure to greenness and particulate matter of different size fractions in relation to childhood rhinitis - A multi-center study in China

The impact of early life exposure to residential greenness on childhood rhinitis and its interaction with particulate matter (PM) of different size fractions remain inconsistent. Herein, we recruited 40,486 preschool children from randomly selected daycare centers in 7 cities in China from 2019 to 2020, and estimated exposure to residential greenness by the normalized difference vegetation index (NDVI) with a 500 m buffer. Exposure to ambient PM (PM1, PM2.5, and PM10) was evaluated using a satellite-based prediction model (daily, at a resolution of 1 km × 1 km). By mixed-effect logistic regression, NDVI values during pregnancy, in the first (0–1 year old) and the second (1–2 years old) year of life were negatively associated with lifetime rhinitis (LR) and current rhinitis (CR) (P < 0.001). PM in the same time windows was associated with increased risks of LR and CR in children, with smaller size fraction of PM showing greater associations. The negative associations between prenatal and postnatal NDVI and LR and CR in preschool children remained robust after adjusting for concomitant exposure to PM, whereas the associations of postnatal NDVI and rhinitis showed significant interactions with PM. At lower levels of PM, postnatal NDVI remained negatively associated with rhinitis and was partly mediated by PM (10.0–40.9 %), while at higher levels of PM, the negative associations disappeared or even turned positive. The cut-off levels of PM were identified for each size fraction of PM. In conclusion, prenatal exposure to greenness had robust impacts in lowering the risk of childhood rhinitis, while postnatal exposure to greenness depended on the co-exposure levels to PM. This study revealed the complex interplay of greenness and PM on rhinitis in children. The exposure time window in prenatal or postnatal period and postnatal concomitant PM levels played important roles in influencing the associations between greenness, PM and rhinitis.

Simulating the impact of particulate matter exposure on health-related behaviour: A comparative study of stochastic modelling and personal monitoring data.

Epidemiological and exposure studies concerning particulate matter (PM) often rely on data from sparse governmental stations. While low-cost personal monitors have some drawbacks, recent developments have shown that they can provide fairly accurate and fit-for-purpose data. Comparing a stochastic, i.e., agent-based model (ABM), with environmental, biometric and activity data, collected with personal monitors, could provide insight into how the two approaches assess PM exposure and dose. An ABM was constructed, simulating a PM exposure/dose assessment of 100 agents. Their actions were governed by inherent probabilities of performing an activity, based on population data. Each activity was associated with an intensity level, and a PM pollution level. The ABM results were compared with real-world results. Both approaches had comparable results, showing similar trends and a mean dose. Discrepancies were seen in the activities with the highest mean dose values. A stochastic model, based on population data, does not capture well some specifics of a local population. Combined, personal sensors could provide input for calibration, and an ABM approach can help offset a low number of participants. Implementing a function of agents influencing others transport choice, increased the importance of cycling/walking in the overall dose estimate. Activists, agents with an increased transport influence, did not play an important role at low PM levels. As concentrations rose, higher shares of activists (and their influence) caused the dose to increase. Simulating a person's PM exposure/dose in different scenarios and activities in a virtual environment provides researchers and policymakers with a valuable tool.

Impact of ventilation type on indoor generated PM and VOC levels for different indoor activities

Residential ventilation systems target in an energy efficient manner an indoor atmosphere fulfilling people’s desired comfort requirements with regard to CO2, temperature, and RH. However, the reach of an indoor atmosphere is not limited to comfort only. Ensuring a healthy indoor atmosphere reducing the risk of acute and chronic diseases caused by the inhaled air is also of importance. A number of elements contribute to indoor air pollution, such as: Volatile Organic Compounds (VOCs), infectious aerosols, and Particulate Matter (PM). These elements combined with the larger proportion of time spent indoors by humans put an emphasis on creating healthy spaces indoors. This investigation treats and discusses in-situ indoor measurements with the Renson Sense of PM1,2.5,4,10, and VOCs caused during the following activities: induction cooking of a typical European meal, vacuuming, and burning of regular and scented candles. All activities were carried out according to a fixed schedule. Both PM and VOC were measured in several rooms of a single, airtight dwelling in Belgium while the following ventilation options were considered: no ventilation, window ventilation, intensive ventilation via a cooker hood, Mechanical Extract Ventilation (MEV = natural supply, mechanical exhaust), and Mechanical Ventilation with Heat Recovery (MVHR = mechanical supply and exhaust). The exhaust flow rate of both MEV and MVHR was set identical to avoid the impact of different air exchange rates on building level. The following main findings were derived from the results. Particle diameters <1 µm (PM1) were dominantly present during all activities and for all considered ventilation options, possibly due to the sensor technology. The spread of cooking-related PM was confined to the floor where the activity took place, and a cooking hood was most effective in reducing PM, as could be expected. Furthermore, no ventilation exhibited logically the slowest decay of PM1, whereas this was most pronounced for window ventilation followed by an equal decay for MEV and MVHR. Burning scented candles led to higher PM levels compared to regular candles, while the PM peak was observed for both when extinguishing the candle. The spread of PM from burning candles was also restricted to the floor where the activity took place, window ventilation clearly reduced the spreading throughout the floor compared to the other ventilation options. Vacuuming activity created much lower PM levels compared to induction cooking and burning candles and therefore the spread of this PM throughout the dwelling was generally non-significant. Regarding VOC, the impact from induction cooking and burning candles was apparent in contrast to vacuuming for all considered ventilation conditions. Next to this, the spread of VOC throughout the building was more limited compared to PM.

Cardiovascular Mortality, Habitual Exercise, and Particulate Matter 2.5 Exposure: A Longitudinal Cohort Study

Habitual exercise may amplify the respiratory uptake of air pollutants in the lung, exacerbating the adverse effects of air pollution. However, it is unclear whether this can reduce the health benefits of habitual exercise (referred to as leisure-time exercise). Thus, the combined effects of habitual exercise and chronic exposure to ambient fine particulate matter 2.5 on cardiovascular mortality were examined among adults in Taiwan. A total of 384,128 adults were recruited between 2001 and 2016 and followed up to May 31, 2019. Participants' vital status was obtained by matching their unique identification numbers with records of cardiovascular death in the National Death Registry of Taiwan. A time-varying Cox regression model was used to analyze the data. Analyses were conducted in 2021. Cardiovascular death risks were inversely associated with habitual exercise and positively associated with chronic exposure to particulate matter 2.5. The beneficial effects of habitual exercise on cardiovascular mortality were not modified by chronic exposure to particulate matter 2.5. Inactive participants with high particulate matter 2.5 exposure exhibited a 123% higher risk of cardiovascular death than high-exercise-group participants exposed to low levels of particulate matter 2.5 (95% CI=89, 163). High level of habitual exercise combined with low exposure level of ambient particulate matter 2.5 is associated with the lowest risk of cardiovascular death. A higher level of habitual exercise is associated with a lower risk of cardiovascular death at all levels of particulate matter 2.5 exposure studied. The results indicate that habitual exercise is a safe health promotion strategy even for people residing in relatively polluted regions.

Characteristics of Atmospheric Compounds based on Regional Multicorrelation Analysis in Honam Area

Particulate Matter (PM) in the atmosphere has serious impacts on human health and the global environmental systems. To reduce anthropogenic PM emissions is of importance to protect public health. In this study, the variation of concentrations in PM&lt;sub&gt;2.5&lt;/sub&gt;, NO&lt;sub&gt;2&lt;/sub&gt;, and O&lt;sub&gt;3&lt;/sub&gt; of Honam region over the past 6 years (2016-2021) was investigated. A statistical approach (i.e., hierarchical cluster analysis) was performed to present their spatial relationships. As a result, the high concentration of PM&lt;sub&gt;2.5&lt;/sub&gt; in Iksan-si was found in sources of primary pollutants emitted from industrial complexes and ammonia from large-scale livestock complexes. The high concentration periods of PM&lt;sub&gt;2.5&lt;/sub&gt; with lower concentrations of NO&lt;sub&gt;2&lt;/sub&gt; and O&lt;sub&gt;3&lt;/sub&gt; can be seasonal and secondary PM product contributions. In addition, the concentration of O&lt;sub&gt;3&lt;/sub&gt; in Buan-gun and Wanju-gun with lower PM levels can be the effect of emission of volatile organic compounds (VOC&lt;sub&gt;S&lt;/sub&gt;) from sources. It is necessary to strengthen management for reducing emissions by sources and to establish a policy to control precursors of the atmospheric contaminants.

Chemical explosion, COVID-19, and environmental justice: Insights from low-cost air quality sensors

ObjectivesTo examine the impact of the Intercontinental Terminals Company (ITC) fire and COVID-19 on airborne particulate matter (PM) concentrations and the PM disproportionally affecting communities in Houston using low-cost sensors. MethodsWe compared measurements from a network of low-cost sensors with a separate network of monitors from the Environmental Protection Agency (EPA) in the Houston metropolitan area from Mar 18, 2019, to Dec 31, 2020. Further, we examined the associations between neighborhood-level sociodemographic status and air pollution patterns by linking the low-cost sensor data to EPA environmental justice screening and mapping systems. FindingsWe found increased PM levels during ITC fire and pre-COVID-19, and lower PM levels after the COVID-19 lockdown, comparable to observations from the regulatory monitors, with higher variations and a greater number of locations with high PM levels detected. In addition, the environmental justice analysis showed positive associations between higher PM levels and the percentage of minority, low-income population, and demographic index. ImplicationOur study indicates that low-cost sensors provide pollutant measures with higher spatial variations and a better ability to identify hot spots and high peak concentrations. These advantages provide critical information for disaster response and environmental justice studies. SynopsisWe used measurements from a low-cost sensor network for air pollution monitoring and environmental justice analysis to examine the impact of anthropogenic and natural disasters.

Evaluation of a new low-cost particle sensor as an internet-of-things device for outdoor air quality monitoring

ABSTRACT Many low-cost particle sensors are available for routine air quality monitoring of PM2.5, but there are concerns about the accuracy and precision of the reported data, particularly in humid conditions. The objectives of this study are to evaluate the Sensirion SPS30 particulate matter (PM) sensor against regulatory methods for measurement of real-time particulate matter concentrations and to evaluate the effectiveness of the Intelligent AirTM sensor pack for remote deployment and monitoring. To achieve this, we co-located the Intelligent AirTM sensor pack, developed at Clemson University and built around the Sensirion SPS30, to collect data from July 29, 2019, to December 12, 2019, at a regulatory site in Columbia, South Carolina. When compared to the Federal Equivalent Methods, the SPS30 showed an average bias adjusted R2 = 0.75, mean bias error of −1.59, and a root mean square error of 2.10 for 24-hour average trimmed measurements over 93 days, and R2 = 0.57, mean bias error of −1.61, and a root mean square error of 3.029, for 1-hr average trimmed measurements over 2300 hours when the central 99% of data was retained with a data completeness of 75% or greater. The Intelligent AirTM sensor pack is designed to promote long-term deployment and includes a solar panel and battery backup, protection from the elements, and the ability to upload data via a cellular network. Overall, we conclude that the SPS30 PM sensor and the Intelligent AirTM sensor pack have the potential for greatly increasing the spatial density of particulate matter measurements, but more work is needed to understand and calibrate sensor measurements. Implications: This work adds to the growing body of research that indicates that low-cost sensors of particulate matter (PM) for air quality monitoring has a promising future, and yet much work is left to be done. This work shows that the level of data processing and filtering effects how the low-cost sensors compare to existing federal reference and equivalence methods: more data filtering at low PM levels worsens the data comparison, while longer time averaging improves the measurement comparisons. Improvements must be made to how we handle, calibrate, and correct PM data from low-cost sensors before the data can be reliably used for air quality monitoring and attainment.

Do Budget Cigarettes Emit More Particles? An Aerosol Spectrometric Comparison of Particulate Matter Concentrations between Private-Label Cigarettes and More Expensive Brand-Name Cigarettes.

Private-label cigarettes are cigarettes that belong to the retailer itself. Private-label cigarettes from discounters or supermarkets are cheaper than brand-name cigarettes, and their lower price has allowed them to garner an ever-increasing share of the tobacco product market, especially among lower socioeconomic groups. Particulate matter (PM), a considerable component of air pollution, is a substantial health-damaging factor. Smoking is the primary source of PM in smokers’ homes. In a 2.88 m3 measuring chamber, the PM emission fractions PM10, PM2.5, and PM1 from three private-label cigarette brands and three brand-name cigarette brands with identical nicotine, tar, and carbon monoxide content were measured and compared to those of a reference cigarette by laser aerosol spectroscopy. All cigarette brands emitted PM in health-threatening quantities. The measurement results ranged from 1394 µg/m3 to 1686 µg/m3 PM10, 1392 µg/m3 to 1682 µg/m3 PM2.5, and 1355 µg/m3 to 1634 µg/m3 PM1, respectively. Only one private-label brand differed significantly (p < 0.001) from the other cigarette brands, which were tested with slightly lower PM levels. All other brands differed only marginally (not significant, p > 0.05) from one another. Significant (p < 0.05) negative correlations between private-label and brand-name cigarettes were found for PM10, PM2.5, and PM1 when accounting for tobacco filling densities, and for PM1 when accounting for filter lengths. The especially health-hazardous fraction PM1 accounted for the largest proportion of PM emissions from the cigarettes tested. The results of this study suggest that- cheaper tobacco products are as harmful as more expensive ones, at least regarding PM emissions. This highlights the importance of anti-smoking campaigns, especially for lower socioeconomic groups, where smoking is more widespread. Governments should reduce the price gap between cheap and more expensive tobacco products by implementing specific tobacco taxes. In such a case, at increasing prices of tobacco products, a downward shift to private-label cigarettes would probably decrease.

Park municipalities and air quality

In Italy, 23 percent of the 7,903 municipalities include protected areas, while 6.4 percent (which we define as park municipalities) national parks. We investigate the relationship between park areas and quality of air and find that park municipalities experienced far lower levels of air pollution in the last three years, the gross difference ranging from 25 to 30 percent lower levels of particulate matter (PM10 and PM2.5) and three times lower levels of nitrogen dioxide. In our econometric analysis we find that part (but not all) of this difference depends on the lower population density and manufacturing activity in municipalities with national parks. We as well show that park municipalities have progressively reduced particulate matter over the last three years and that parks have a “green lung” function since, in non-park municipalities, air pollution grows in the distance from national parks. Based on our average of estimated parameters of the impact of the main air pollutants on mortality in the literature we calculate that living in park municipalities reduces mortality rates by around 10 percent.

Analysis of Restaurant Indoor Air Quality in Smoking-Allowed Vs. Smoke-Free College Communities

This study examined the indoor air quality of restaurants in two cities with universities, one smoke-free (n=15) and one that allowed smoking (n=17). Results indicated that restaurants protected by smoke-free ordinance had significantly (p=.036) lower levels of particulate matter (13.10±10.33 ug/m3) compared to restaurants which allowed smoking (130.72±212.64 ug/m3). Mean particulate matter within smoking-allowed restaurants was caused by as few as three cigarettes being smoked at one time. Based on the EPA Air Quality Index, 70.6% of smoking-allowed restaurants yielded an unhealthy classification compared to only 6.7% of smoke-free restaurants (p=.005). Smoke-free ordinances provide effective protection from indoor air pollution.

Complex Characterization of Fine Fraction and Source Contribution to PM2.5 Mass at an Urban Area in Central Europe

It is well documented that Southern Poland is one of the most polluted areas in Europe due to the highest airborne concentrations of particulate matter (PM). Concentrations of fine particles are especially high in winter. Apart from detailed number concentrations, it is essential to accurately identify and quantify specific particulate pollution sources. Only a few Polish research centers are involved in such experiments—among them is Krakow research group. For the most part, research focuses on collecting 24-h average samples from stationary PM samplers at ambient monitoring sites and quantifying the specific elements and chemical constituents in PM. This approach includes modeling methods that can use the variability in physical and chemical PM characteristics as an input dataset to identify possible sources of the particles. The objective of this paper is to provide research results based on data collected from June 2018 to May 2019 from a single monitoring station at a central urban site. Careful comparison of data obtained prior to a 2019 law prohibiting solid fuel burning in the city of Krakow with data (2019–2020) when a regulation went into effect should indicate progress by noting lower PM levels. This work has shown that the method applied and Krakow results might be of interest to the broader community in regions of high PM concentration.

Changes in Biomarkers of Exposure on Switching From a Conventional Cigarette to the glo Tobacco Heating Product: A Randomized, Controlled Ambulatory Study.

IntroductionTobacco heating products (THPs) generate lower machine yields of toxicants compared to those found in conventional cigarette smoke. During use, these products are likely to expose users to lower levels of particulate matter and harmful and potentially harmful compounds compared with smoking cigarettes.Aims and MethodsThis randomized, controlled study is investigating whether biomarkers of exposure (BoE) to smoke toxicants are reduced when smokers switch from smoking cigarettes to using the glo THP in a naturalistic, ambulatory setting. Control groups include smokers who are abstaining from cigarette smoking and never-smokers. At a baseline study visit, 24-hour urine samples and spot blood samples were taken for BoE analysis, and exhaled carbon monoxide was also measured. N-(2-cyanoethyl) valine (CEVal) was used as a marker of compliance in subjects asked to refrain from combustible cigarette smoking. Subjects are being followed up at periodic intervals for 360 days; this article presents data following a planned interim analysis at day 90.ResultsIn continuing smokers, BoE remained stable between baseline (day 1) and day 90. In both per-protocol and CEVal-compliant analysis populations, reductions in BoE were observed in subjects switching to using glo or undergoing smoking cessation. These reductions were statistically significant for a number of BoE when switching to glo was compared with continued smoking. Furthermore, in both populations, reductions observed in subjects switching to using glo were comparable to those seen with smoking cessation and were also to levels similar to those seen in never-smokers.Conclusionglo is a reduced-exposure tobacco product.ImplicationsThis clinical study builds on a previous 5-day confinement study and demonstrates that when smokers switched from smoking combustible cigarettes to using the glo THP in a naturalistic, ambulatory setting, their exposure to tobacco smoke toxicants was significantly decreased. For most BoE examined, this was to the same extent as that seen when a control group of smokers ceased cigarette smoking, or even to levels seen in never-smoker controls. This indicates that glo is a reduced-exposure product with the potential to be a reduced-risk tobacco product, when used by smokers whose cigarette consumption is displaced completely.Clinical trial registrationISRCTN81075760.

Long-term exposure to ambient air pollution is associated with coronary artery calcification among asymptomatic adults.

We investigated the effects of exposure to very low levels of particulate matter <2.5 µm (PM2.5) and nitrogen dioxide (NO2) on coronary calcium score (CCS) in asymptomatic adults who are free of coronary artery disease (CAD). This study included 606 asymptomatic adults (49% men, aged 56±7 years) recruited from communities in three states of Australia during 2017-2018. CCS was measured using coronary computed tomography scan at recruitment. Annual PM2.5 and NO2 concentrations were estimated on the year before recruitment using statistical exposure models and assigned to each participant's residential address. Medical history, physical measurements, biochemistry, and sociodemographic and socioeconomic status were also recorded. Median concentrations of PM2.5 and NO2 were 6.9 µg/m3 [interquartile range (IQR) 6.0-7.7)] and 3.1 ppb [IQR 2.2-4.5], respectively. Of the 606 participants, 16% had high CCS (≥100) and 4% had very high CCS (≥400). Exposure to higher PM2.5 (per µg/m3) was significantly associated with greater odds of having high CCS (OR 1.20, 95% CI 1.02-1.43) and very high CCS (OR 1.55, 95% CI 1.05-2.29). Similar associations were observed for NO2 and high CCS (OR 1.14, 95% CI 1.02-1.27) and very high CCS (OR 1.23, 95% CI 1.07-1.51). These findings were robust to adjustment for sociodemographic factors, traditional cardiovascular risk factors, renal function, education, and socio-economic status. Ambient air pollution even at low concentration was associated with degree of coronary artery calcification among asymptomatic low cardiovascular risk adults, independent of other risk factors. These findings suggest that air pollution is one of the residual risk factors of CAD.

Impacts of Exhaust Transfer System Contamination on Particulate Matter Measurements

As the measurement of low levels of particulate matter (PM) and solid particulate number (PN) from light-duty vehicles becomes more critical, it is becoming more important to understand the potential impacts of exhaust transfer system contamination. This phenomenon occurs when, as it relates to vehicle emission testing, particles deposit and semi-volatile materials are adsorb onto the inner surfaces of the exhaust transfer system, which includes the vehicle exhaust pipe, the exhaust transfer line, and the constant volume sampling (CVS) system, and may subsequently re-entrain and desorb in subsequent vehicle tests. A soot loading cycle was successfully developed and resulted in 36 to 8600 mg of PM mass passing through the CVS tunnel. The results from cleaning tests suggested that majority of particles released during the cleaning tests are semi-volatiles with little presence of soot. A series of chassis dynamometer tests were conducted to characterize the differences between “clean” and “contaminated” sampling system and their impact on low level PM measurements. The results from this study show no measurable PM mass impacts between the “dirty” and clean tunnel conditions that were observed until after a high emitter was tested (80–120 mg/mi diesel vehicle).

The Effect of Particulate Matter Exposure on the Inflammatory Airway Response of Street Runners and Sedentary People

Physical exercise promotes many health benefits. However, its effects are not well known in a polluted environment. Thus, this study aimed to compare upper airway inflammatory responses between street runners and sedentary individuals. Twenty-eight volunteers were recruited: runners (n = 14) and sedentary individuals (n = 14), who lived and worked in the same metropolitan area of São Paulo, Brazil. Particulate matter (PM) levels were monitored ten weeks before winter (low PM levels) and ten weeks after the beginning of winter (high PM levels) [PM10 (p &lt; 0.0001) and PM2.5 (p &lt; 0.0001)]. The cytokines (TNF-α, IL-6, IL-10, and IL-17A) levels in the nasal lavage and fractional exhaled nitric oxide (FeNO) were taken at the beginning of the winter (baseline) and ten weeks afterwards (after ten weeks of high PM exposure). IL-6 concentration increased in both runners (p = 0.037) and sedentary individuals (p = 0.027) after high PM exposure compared to the baseline. IL-10 concentration increased in sedentary individuals (p = 0.037) while IL-17A levels were increased in runners (p = 0.001) after high PM exposure compared to the baseline. FeNO levels decreased in runners (p = 0.025) after high PM exposure compared to the baseline. Outdoor endurance training acts as an inducer of a differentiated immune response in the upper airways of runners compared to individuals with a sedentary lifestyle from the same community after elevated PM exposure.

Differences in plant metabolites and microbes associated with Azadirachta indica with variation in air pollution

Mitigation of air pollution by plants is a well-established phenomenon. Trees planted on the roadside are known to reduce particulate matter pollution by about 25%. In an urban ecosystem, especially in a metropolitan city such as Delhi, roadside trees are constantly exposed to air pollution. We, therefore, evaluated the effect of air pollution on a common Indian roadside tree, Neem (Azadirachta indica), and its associated microbes in areas with high and low levels of particulate matter (PM) pollution in Delhi. We hypothesized that alteration in the air quality index not only influences plant physiology but also its microbiome.A 100-fold increase in the number of epiphytic and 10–100 fold increase in endophytic colonies were found with 1.7 times increase in the level of pollutants. Trees in the polluted areas had an abundance of Salmonella, Proteus and Citrobacter, and showed increased secondary metabolites such as phenols and tannins as well as decreased chlorophyll and carotenoid. The number of unique microbes was positively correlated with increased primary metabolites.Our study thus indicates that, alteration in air quality affects the natural micro-environment of plants. These results may be utilized as sustainable tools for studying plant adaptations to the urban ecosystem.

Exposure of trophoblast cells to fine particulate matter air pollution leads to growth inhibition, inflammation and ER stress.

Ambient air pollution is considered a major environmental health threat to pregnant women. Our previous work has shown an association between exposure to airborne particulate matter (PM) and an increased risk of developing pre-eclamspia. It is now recognized that many pregnancy complications are due to underlying placental dysfunction, and this tissue plays a pivotal role in pre-eclamspia. Recent studies have shown that PM can enter the circulation and reach the human placenta but the effects of PM on human placental function are still largely unknown. In this work we investigated the effects of airborne PM on trophoblast cells. Human, first trimester trophoblast cells (HTR-8/SV) were exposed to urban pollution particles (Malmö PM2.5; Prague PM10) for up to seven days in vitro and were analysed for uptake, levels of hCGβ and IL-6 secretion and proteomic analysis. HTR-8/SVneo cells rapidly endocytose PM within 30 min of exposure and particles accumulate in the cell in perinuclear vesicles. High doses of Prague and Malmö PM (500–5000 ng/ml) significantly decreased hCGβ secretion and increased IL-6 secretion after 48 h exposure. Exposure to PM (50 ng/ml) for 48h or seven days led to reduced cellular growth and altered protein expression. The differentially expressed proteins are involved in networks that regulate cellular processes such as inflammation, endoplasmic reticulum stress, cellular survival and molecular transport pathways. Our studies suggest that trophoblast cells exposed to low levels of urban PM respond with reduced growth, oxidative stress, inflammation and endoplasmic reticulum stress after taking up the particles by endocytosis. Many of the dysfunctional cellular processes ascribed to the differentially expressed proteins in this study, are similar to those described in PE, suggesting that low levels of urban PM may disrupt cellular processes in trophoblast cells. Many of the differentially expressed proteins identified in this study are involved in inflammation and may be potential biomarkers for PE.

Performance analysis and exhaust emissions of aegle methyl ester operated compression ignition engine

This paper reports on a study of the use of aegle methyl ester biodiesel (B20, B40, B100), as an alternative fuel in light of it being more eco-friendly as compared to diesel. The B20, B40, and B100 blend of AME biodiesel was investigated by numerical simulation using Diesel-RK software as compared to diesel (B0). To optimize the use of aegle methyl ester (AME) biodiesel in diesel engines. The numerical results show slightly higher brake specific fuel consumption, CO2 emission as well as NOX emission by 3.0%, 4.5% and 8.5% respectively. Moreover, there is also an immediate reduction in particulate matter emission, smoke emission and soot emission by 21.4%, 20.83% and 24.41% respectively. There is a consistency between the experimental results and numerical results available in the literature indicating the predictive capability of the model. The result also reveal that the indicated thermal efficiency and mechanical efficiency of aegle methyl ester biodiesel fuelled engine has been reduced however, an increase in SFC with higher fuel injection pressure of 220 bar is also observed. In addition low levels of particulate matter and smoke emissions were observed for the B20 blend at full engine load with a higher fuel injection pressure of 220 bar.

Particulate matter-associated micronuclei frequencies in maternal and cord blood lymphocytes.

Studies associate particulate matter (PM) exposure with pulmonary, cardiovascular, and neurologic diseases. Elevated levels of coarse (PM10) and fine (PM2.5) PM have been reported in the Mexico City metropolitan area during the last two decades. There is limited information if these conditions affect newborns. We associated maternal exposure to PM reported by the monitoring stations considering the place of residence of each participant with the presence of genotoxic damage (cytome analysis) in maternal and umbilical cord blood (UCB) lymphocytes. Eighty-four healthy women in their last quarter of pregnancy met the inclusion criteria. Each volunteer exposure was estimated according to the average PM2.5 and PM10 levels during the last month of gestation. The micronuclei (MN) frequencies in UCB lymphocyte cultures ranged between 0 and 9. They also showed lower cell proliferation indexes than their mothers. There was a strong correlation between the maternal and the UCB MN frequency (ρ = 0.3767, P = 0.0002). Multiple regression analysis including PM10 and PM2.5 levels, maternal age, and occupation, showed a significant and positive association between UCB MN frequency and PM2.5. A statistically significant increase in the MN frequency in both maternal and UCB lymphocytes was observed in samples obtained during the dry season (higher PM levels) as compared with the MN frequency in blood samples obtained during the rainy season (lower PM levels). These results suggest that PM, mainly PM2.5 , can cross the placenta causing DNA damage in fetal cells which may increase the potential for diseases during childhood or adult life. Environ. Mol. Mutagen. 60:421-427, 2019. © 2019 Wiley Periodicals, Inc.