Terms Of Air Pollution Research Articles

Short Term Air Pollution Exposure is Associated with Hospital Admissions and Emergency Department Visits for Individuals with Sickle Cell Disease

Short Term Air Pollution Exposure is Associated with Hospital Admissions and Emergency Department Visits for Individuals with Sickle Cell Disease

Short term air pollution exposure during pregnancy and associations with maternal immune markers

BackgroundAir pollution exposure during pregnancy has been associated with numerous adverse pregnancy, birth, and child health outcomes. One proposed mechanism underlying these associations is maternal immune activation and dysregulation. We examined associations between PM2.5 and NO2 exposure during pregnancy and immune markers within immune function groups (TH1, TH2, TH17, Innate/Early Activation, Regulatory, Homeostatic, and Proinflammatory), and examined whether those associations changed across pregnancy. MethodsIn a pregnancy cohort study (n = 290) in Rochester, New York, we measured immune markers (using Luminex) in maternal plasma up to 3 times during pregnancy. We estimated ambient PM2.5 and NO2 concentrations at participants’ home addresses using a spatial-temporal model. Using mixed effects models, we estimated changes in immune marker concentrations associated with interquartile range increases in PM2.5 (2.88 μg/m3) and NO2 (7.82 ppb) 0–6 days before blood collection, and assessed whether associations were different in early, mid, and late pregnancy. ResultsIncreased NO2 concentrations were associated with higher maternal immune markers, with associations observed across TH1, TH2, TH17, Regulatory, and Homeostatic groups of immune markers. Furthermore, the largest increases in immune markers associated with each 7.82 ppb increase in NO2 concentration were in late pregnancy (e.g., IL-23 = 0.26 pg/ml, 95% CI = 0.07, 0.46) compared to early pregnancy (e.g., IL-23 = 0.08 pg/ml, 95% CI = −0.11, 0.26). ConclusionsResults were suggestive of NO2-related immune activation. Increases in effect sizes from early to mid to late pregnancy may be due to changes in immune function over the course of pregnancy. These findings provide a basis for immune activation as a mechanism for previously observed associations between air pollution exposure during pregnancy and reduced birthweight, fetal growth restriction, and pregnancy complications.

Emerging Stroke Risk Factors: A Focus on Infectious and Environmental Determinants.

This review focuses on emerging risk factors for stroke, including air pollution and climate change, gut microbiota, high altitude, and systemic infection. Up to 14% of all stroke-associated mortality is attributed to air pollution and is more pronounced in developing countries. Fine particulate matter and other air pollutants contribute to an increased stroke risk, and this risk appears to increase with higher levels and duration of exposure. Short term air pollution exposure has also been reported to increase the stroke risk. The gut microbiota is a complex ecosystem of bacteria and other microorganisms that reside in the digestive system and affect multiple body systems. Disruptions in the gut microbiota may contribute to stroke development, possibly by promoting inflammation and atherosclerosis. High altitudes have been associated with erythrocytosis and cerebrovascular sinus thrombosis, but several studies have reported an increased risk of thrombosis and ischemic stroke at high altitudes, typically above 3000 m. Systemic infection, particularly infections caused by viruses and bacteria, can also increase the risk of stroke. The risk seems to be greatest in the days to weeks following the infection, and the pathophysiology is complex. All these emerging risk factors are modifiable, and interventions to address them could potentially reduce stroke incidence.

BTEX OCCURRENCE IN THE INDOOR AIR OF BEAUTY SALONS – PRELIMINARY RESEARCH

This study aimed to identify and carry out a preliminary assessment of the health exposure ofemployees working in beauty salons to selected compounds from the BTEX group. The selectedsalons were all situated in the Silesian Voivodeship, recognized as one of the most polluted regionin Poland and European hot spot area in terms of air pollution. Measurements encompassed weeklymonitoring of marked BTEX compounds in beauty salons specializing in nail styling, hairdressingand cosmetics. As an internal substrate, measurements were also taken in a children’s hairdressingsalon where no chemical products were used; also a weekly measurement was performed foroutdoor air to look for outdoor background BTEX concentrations.For BTEX determination, Tenax sorbent tubes insertion was employed. The collected samples wereanalysed using a Clarus 500 gas chromatograph with a flame ionization detector (FID) connectedto a Perkin Elmer Turbo-Matrix 100 thermal desorber . Toluene concentrations were found to benotably elevated, reaching up to 73.19 μg/m in adult hairdresser salons, representing an orderof magnitude higher than that found in indoor background (children’s hairdresser) and outdoorbackground. Importantly, the concentrations of the measured BTEX compounds remained belowthe acceptable levels defined by the National Institute for Occupational Safety and Health (NIOSH).Among the individual BTEX compounds, nail treatment salons exhibited the highest meanconcentrations for benzene; m,p-xylene; n-propylbenzene; styrene; isopropylbenzene; and1,3,5-trimethylbenzene. Conversely, cosmetic salons registered the highest mean concentrationof ethylbenzene; o-xylene; and n-propylbenzene. The results indicate a chronic exposure ofsalon employees to the tested compounds, with heightened levels particularly noticeable amongindividuals with extensive professional experience. These findings underscore the importance ofongoing monitoring and occupational health measures in beauty salons, emphasizing the potentialrisks associated with long-term exposure to BTEX compounds.

Air pollution and cerebrovascular diseases

Amongst the primary environmental issues affecting global health, air pollution is considered the leading cause of concern. Globally, around 800,000 deaths were attributed to air pollution according to WHO. Evidence suggests that there has been strong association of air pollution with stroke. Approximately, 25% of the stroke mortality was due to air pollution according to a study in 2013. The aim of this review is to analyze association of stroke and air pollution and its burden globally with a special focus on South Asia along with its association with COVID 19 pandemic. There is currently a lot of research that links air pollution to cardiovascular disorders including stroke. Short term and long-term air pollution exposure has been shown to increase the stroke incidence in epidemiological data. It was concluded that air pollution, both gaseous and particle, show a strong and tight temporal relationship with stroke hospitalizations and death. Even though air pollution poses a significant threat to human health, the great number of countries still fail to achieve internationally agreed air quality standards. Air pollution should be recognized amongst the most significant controllable risk factors for cardiovascular and cerebrovascular disease prevention and treatment. Nonetheless, during the last decade, global knowledge of the health implications of air pollution has increased significantly, and the desire for global initiatives to combat air pollution has begun with optimism.

Increased Risk for Hospitalization Associated with Short Term Particle Air Pollution Exposure for California Residents with Sickle Cell Disease

Background: Air pollution is associated with numerous adverse health outcomes in the general population such as asthma exacerbations, pneumonia, myocardial infarction, and stroke. There is a strong association between air pollution and mechanistic processes associated with oxidative stress, vasoconstriction, and inflammation, suggesting a high risk of exposure for those with sickle cell disease (SCD). A small number of published studies have explored this relationship, primarily focusing on children. Only two studies have examined air pollution in the US, both with outcomes among urban area hospitals in Atlanta, GA. None have taken place in California, which has the worst air quality, including the four most polluted cities in year-round particle pollution in the nation. Additionally, all published studies have overlooked more rural exposure areas. Recent advances in environmental exposure assessment have enabled high-resolution predictions of ambient air pollution concentrations in the whole US, making it possible to cover unmonitored suburban and rural areas that were unrepresented in the past. In addition, these high-resolution predictions are more precise surrogates of the personal exposure measures than monitored data. Particulate matter with a diameter of 2.5 microns or less (PM 2.5) is the most harmful pollutant based on current research findings. We hypothesized that short term increases in PM 2.5 exposure were associated with an increased risk for hospitalization among individuals with SCD in California. Methods: We designed a time-stratified case-crossover study to estimate the percent change in risk for hospitalization for SCD complications associated with each 1mg/m 3 increase in PM 2.5 exposure. The zip code of residence was used to spatially link each hospital admission with PM 2.5 exposure using a novel hybrid exposure model allowing for estimated exposure in areas without direct remote sensing. We used conditional logistic regressions to examine the PM 2.5 exposures at 7-day moving average and single lag days (from lag 0 to 6 days) before admission, adjusting for nonlinear confounding effects of air temperature and humidity at the same exposure window. We examined risk for all hospitalizations and specifically for vaso-occlusive pain (VOC) and acute chest syndrome (ACS). Results: From 2000-2016, among 5,835 California residents with SCD, there were 107,450 admissions for sickle cell disease complications with VOC being the most common indication (71.1%). PM 2.5 air pollution data was examined among 2,634 zip codes throughout the state. Residents with SCD were noted to be living among 1,180 zip codes. The daily burden of PM 2.5 was higher in zip codes with residents with SCD (mean 11.5 mg/m 3, standard deviation [SD] 9.0) when compared to zip codes without residents known to have SCD (mean 9.2 mg/m 3, SD 8.6, p<0.001) ( Table 1). Overall, the mean daily burden of PM 2.5 declined in the period of 2010-2016 when compared to that from 2000-2009. However, the daily mean PM 2.5 concentration remained higher in zip codes with individuals with SCD. No significant association was seen in examining the week-long exposure to PM 2.5 and increase risk in hospitalizations for any indication over the entire study period (2000-2016). However, when examining the more contemporary period of 2010-2016, we identified that each 1mg/m 3 increase in PM 2.5 was associated with 0.22% increased risk for SCD hospitalization (Confidence Interval [CI] 0.02-0.42, p=0.03) 3 days prior to admission. We observed a 0.26% increased risk for hospitalization for VOC with each 1 mg/m 3 increase in PM 2.5 exposure (CI 0.02-0.49, p=0.03) at lag day 3 (Figure 1). No effect was seen with PM 2.5 on hospitalizations for ACS during any time period. Discussion: Our study suggests that short term air pollution exposure may be a trigger for hospitalization for individuals with SCD. In particular this effect is seen in the more recent years with a lower daily average PM 2.5 burden overall, suggesting attention may be needed well below Environmental Protection Agency (EPA) thresholds. Consistent with previous studies, lag day 3 PM 2.5 exposure is associated with an increased risk for hospitalization for VOC. These results may have important implications in understanding risk factors for hospitalization for children and adults with SCD.

Do women perceive pedestrian path attractiveness differently from men?

The objective of this work is investigating on differences in pedestrians’ perceptions in terms of gender. Specifically, we want to verify differences between male and female in perceiving aspects characterizing pedestrian paths and influencing their satisfaction, perceived service quality, and behavioural intentions. We propose a methodology based on Partial Least Squares Structural Equation Modelling (PLS-SEM) approach. From the model calibration we derived different coefficients for male and female, representing the importance that each category of users gives to the various aspects characterizing the paths. Data were collected through a sample survey addressed to pedestrians walking on paths placed in an urban area of the southern Italy. We discovered interesting findings about gender differences. In general, females are more sensitive than males concerning many important aspects such as environmental aspects in terms of air pollution and noise, or personal security from robbery or theft, or presence of furnishing along the path and cleanliness of the environment. On the other hand, male consider more the continuity of pedestrian path and the condition of the walking surface, as well as the nuisance due to the vehicle flow. In terms of similarities in perceptions, male and female equally appreciated the comfort due to the presence of trees providing shade along the path. The findings from the model could be useful for planners, who should invest on those aspects considered as important by both the categories, but also on the aspects that determine an inequality between male and female. As an example, since women do not feel secure along those paths, planners could improve this aspect in such a way as to make paths attractive to both women and men, as well as the aspects considered more relevant for men, to incentivize pedestrian mobility.

Air pollution particulate matter (PM2.5) prediction in South African cities using machine learning techniques.

Air pollution contributes to the most severe environmental and health problems due to industrial emissions and atmosphere contamination, produced by climate and traffic factors, fossil fuel combustion, and industrial characteristics. Because this is a global issue, several nations have established control of air pollution stations in various cities to monitor pollutants like Nitrogen Dioxide (NO2), Ozone (O3), Sulfur Dioxide (SO2), Carbon Monoxide (CO), Particulate Matter (PM2.5, PM10), to notify inhabitants when pollution levels surpass the quality threshold. With the rise in air pollution, it is necessary to construct models to capture data on air pollutant concentrations. Compared to other parts of the world, Africa has a scarcity of reliable air quality sensors for monitoring and predicting Particulate Matter (PM2.5). This demonstrates the possibility of extending research in air pollution control. Machine learning techniques were utilized in this study to identify air pollution in terms of time, cost, and efficiency so that different scenarios and systems may select the optimal way for their needs. To assess and forecast the behavior of Particulate Matter (PM2.5), this study presented a Machine Learning approach that includes Cat Boost Regressor, Extreme Gradient Boosting Regressor, Random Forest Classifier, Logistic Regression, Support Vector Machine, K-Nearest Neighbor, and Decision Tree. Cat Boost Regressor and Extreme Gradient Boosting Regressor were implemented to predict the latest PM2.5 concentrations for South African Cities with recording stations using past dated recordings, then the best performing model between the two is used to predict PM2.5 concentrations for South African Cities with no recording stations and also to predict future PM2.5 concentrations for South African Cities. K-Nearest Neighbor, Logistic Regression, Support Vector Machine, Decision Tree, and Random Forest Classifier were implemented to create a system predicting the Air Quality Index (AQI) Status. This study investigated various machine learning techniques for air pollution to analyze and predict air pollution behavior regarding air quality and air pollutants, detecting which areas are most affected in South African cities.

Errors and inaccuracies about celestial bodies in the Greek texts of children’s fiction books about atmospheric pollution

This paper examines children’s fiction books on air pollution in terms of the accuracy of their content in the representation of celestial bodies. The qualitative content analysis identifies and records in the text of 18 books passages containing errors and inaccuracies about celestial bodies. The passages are organized and presented in a category system while also being linked to the possible alternative ideas they may generate in children. The results show that the Earth, the planets, the Sun, and the stars are only sometimes represented based on scientific standards. Finally, the common errors and inaccuracies are presented. At the same time, suggestions are made for using these books in teaching and learning in science and environmental education in order to avoid misconceptions from their students.

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Associations of air pollution and greenness with global burden of breast cancer: an ecological study.

Despite the significance of the associations of air pollution and greenness with the risk of breast cancer, this topic has not been investigated on a global scale. We conducted an ecological study using 7 years of data from 162 countries. Disability-adjusted life years (DALYs) and incidence data were used to represent the breast cancer disease burden. Particulate matter with a diameter < 2.5 μm (PM2.5), ozone (O3), nitrogen dioxide (NO2), and the normalized difference vegetation index (NDVI) were adopted as our exposures. We employed generalized linear mixed models to explore the relationship between air pollution and greenness on breast cancer disease burden. The rate ratio (RR) and its 95% confidence interval (CI) indicate the effect size. There is a positive association between air pollution and the burden of breast cancer disease. Contrarily, per interquartile range increment in NDVI was negatively associated with DALYs and incidence. In terms of air pollutants and breast cancer, NDVI seems to have a significant influence on the relationship between these two conditions. A higher amount of greenness helps to alleviate the negative association of air pollution on breast cancer. PM2.5 and O3 play a mediating role in the relationship between greenness and breast cancer disease burden. In areas with higher levels of greenness, there is a possibility that the inverse association between air pollutants and the burden of breast cancer may be influenced.

The impact of Covid-19 on air quality in Bucharest, Romania

In this study, the authors aimed to assess the air quality within Bucharest City, Romania’s capital, during the Covid-19 pandemic. It was well established that for quite a long period, Bucharest was among the worst Romanian cities in terms of air quality. Thus, in this study, an investigation of the effects of imposed quarantine and lockdown in terms of air pollution was carried out. The levels of the main air pollutants, particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2) and benzene (C6H6), were recorded within the period of January 2020–April 2022 by using six stationary monitoring stations (B-1, B-2, B-3, B-4, B-5 and B-6) belonging to the Romanian National Network for Monitoring Air Quality. During the lockdown period (16 March–14 May 2020), the measurements indicated significant reductions only for PM2.5, nitrogen dioxide and benzene, while for PM10, due to the fact that a sandstorm appeared, the results were unreliable. The results focused on the B-3 and B-6 traffic monitoring stations because road traffic was one of the main sources of pollution in cities. Compared with the 2018–2019 period, during the lockdown, all the air pollutants from all the measuring stations dramatically dropped, highlighting thus the important role of traffic and its significant contribution to air quality depreciation in Bucharest, particularly in terms of nitrogen dioxide pollution. Therefore, the urgent need for decisions to be made in terms of improving the air quality of the city, particularly from a road traffic perspective, arose.

Urban climate and cardiovascular health: Focused on seasonal variation of urban temperature, relative humidity, and PM2.5 air pollution

Seasonal effects on subclinical cardiovascular functions (CVFs) are an important emerging health issue for people living in urban environment. The objectives of this study were to demonstrate the effects of seasonal variations of temperature, relative humidity, and PM2.5 air pollution on CVFs. A total of 86 office workers in Taipei City were recruited, their arterial pressure waveform was recorded by cuff sphygmomanometer using an oscillometric blood pressure (BP) device for CVFs assessment. Results of paried t-test with Bonferroni correction showed significantly increased systolic and diastolic BP (SBP, DBP), central end-systolic and diastolic BP (cSBP, cDBP) and systemic vascular resistance, but decreased heart rate (HR), stroke volume (SV), cardio output (CO), and cardiac index in winter compared with other seasons. After controlling for related confounding factors, SBP, DBP, cSBP, cDBP, LV dp/dt max, and brachial-ankle pulse wave velocity (baPWV) were negatively associated with, and SV was positively associated with seasonal temperature changes. Seasonal changes of air pollution in terms of PM2.5 were significantly positively associated with DBP and cDBP, as well as negatively associated with HR and CO. Seasonal changes of relative humidity were significantly negatively associated with DBP, and cDBP, as well as positively associated with HR, CO, and baPWV. This study provides evidence of greater susceptibility to cardiovascular events in winter compared with other seasons, with ambient temperature, relative humidity, and PM2.5 as the major factors of seasonal variation of CVFs.

The dynamic relationship among economic development, air pollution, and health production in China: the DNSBM efficiency model

China’s economy has grown rapidly in response to the adoption of a high-energy, high-emissions development model, which has led to varying degrees of air pollution; moreover, the corresponding health damage has become a major concern for the public. Studies of the interrelationships between the economy, air pollution, and health often use empirical methods such as regression analysis, to explore the impacts of economic growth and air pollution, human health or air pollution on human health in isolation, and they rarely explore the interactions between the economy, air pollution, and health in terms of efficiency (i.e., the maximum output per unit of input resources that can be produced). Thus, this study constructed a Dynamic Network SBM efficiency model that unifies the production of economic development, air pollution, and health into a single framework. The article reports the findings of a comprehensive study of economic development, air pollution, and health management data for 30 Chinese provinces from 2015 to 2020. The results show that: 1) the overall efficiency (0.693) of China’s two stages from economic production input to healthy output from 2015 to 2020 is low, and there is much room for improvement; 2) the efficiency of economic development (0.729) is higher than the efficiency of health production (0.657), indicating that the health production stage needs to be strengthened; 3) during the study period, China’s PM2.5, SO2, and NOx control efficiency was low, at 0.786, 0.710, and 0.718, respectively, indicating that more effective measures are needed to improve environmental efficiency; and 4) there are significant differences in economic, environmental, and health efficiency across regions. China’s developed eastern provinces are more efficient in terms of economic development, health production, and air pollution control. In contrast, the central and western provinces, which are relatively backward in their economic development, are less efficient. This means that each province should implement sound policies based on its own assessment to promote sustainable economic development while enhancing air pollution mitigation and health promotion.

Türkiye’nin bir sanayi şehrinde konut ısıtmasının hava kirliliğine katkısı

In this study, the contribution of fuels (coal + natural gas) used for residential heating in Kayseri city center to air pollution was investigated. For this reason, the amount of emissions released to the atmosphere was calculated by using the natural gas and coal data used in the residences in the 5 (five) year period between 2015-2019 in the province of Kayseri. In addition, the percentage contribution of both residential heating and industrial point sources to air pollution in terms of emissions was compared. The relationship between annual average emission amounts and National Air Quality Monitoring Network data was also revealed. During the 5 years period, the total amount of emissions originating from the fuels used in residences and industries were 6171 tons for PM, 9049 tons for SO2, and 14179 tons for NOx. It has been evaluated that the decrease in PM10 concentrations and the increase in NOX concentrations from 2015 to 2019 may be related to the increase in natural gas use in the city. When evaluated in terms of emission amounts; it has been revealed that PM and SO2 are mostly released from domestic sources, while NOXs are from industrial sources.

The Relationship Between Competition, Tourism and Sustainable Development: Three Interdependent Topics

In recent years, there has been considerable interest in examining the relationship between tourism and sustainable development. For firms to act friendly against the environment, competition authorities must provide them with the appropriate legal certainty they need to make the necessary investments towards sustainability. Also, energy intensity flows must be kept up more closely since the empirical results point out its substantially positive contribution in terms of air pollution Therefore, policy implications should be strengthened towards more installation of renewable energy and a convergence of environmental policies towards more efficient energy use among EU countries. Energy intensity flows must be kept up more closely since the empirical results point out its substantially positive contribution in terms of air pollution.

Indoor environmental quality in offices and risk of health and productivity complaints at work: A literature review

Many service jobs are carried out in modern offices, with individual offices being increasingly replaced by open-plan settings. The high number of adult people working in office buildings, in most situations sharing the workplace with many others during a considerable part of their daily time, highlights the importance of providing adequate guidance to ensure the quality of office environments. This paper aims to summarize existing data on modern offices' indoor environmental quality (IEQ) conditions in terms of air pollution (volatile organic compounds (VOC), particulate matter and inorganic pollutants), thermal comfort, lighting and acoustics and the respective associations with health and productivity-related outcomes in workers. Evidence shows that although many offices present acceptable IEQ, some office settings can have levels of air pollutants, hygrothermal conditions/thermal comfort and illuminance that do not comply with the existing international standards and recommendations. In addition, findings suggest the existence of significant associations between the assessed IEQ indicators and the risk of detrimental effects on health and productivity of office workers. In particular, airborne particles, CO2, O3 and thermal comfort were linked with the prevalence of sick building syndrome symptoms. Poor lighting and acoustical quality have also been associated with malaise and physiological stress among office workers. Similarly, better productivity levels have been registered for good indoor air quality conditions, in terms of VOC, airborne particles and CO2. Overall, the evidence revised in this work suggests that for promoting health and productivity recommendations for office building managers include actions to ensure that: i) all relevant IEQ indicators are periodically controlled to ensure that levels comply with recommended limit values; ii) declared indoor pollution sources are avoided; iii) adequate ventilation and acclimatization strategies are implemented; and iv) there is the possibility of conduct personalized adjustments to environmental conditions (following workers' preferences).

How much behaviour change is required for the investment in cycling infrastructure to be sustainable? A break-even analysis.

Active travel has gained traction among policy makers as a promising solution to physical inactivity. Returns on active travel investments, including cycling infrastructure, crucially rely on resulting improvements in population behaviours. Estimating the expected economic value that an additional regular cyclist will generate and being able to identify the behaviour change required at the population level to offset the intervention costs is important to inform future investment decisions. The WHO's Health Economic Assessment Tool was employed to conduct a break-even analysis. A case study methodology was used which focused on a real-world construction project of a separated cycleway in the UK. The economic assessment considered physical activity benefits, air pollution, crash risk and carbon emissions in monetary terms. An iterative computational approach was applied to identify the behaviour change (cycling) requirements, and corresponding benefits valued using international dollars, to break even on the investment costs. Sensitivity analyses were conducted to assess robustness of the base-case results. Over a ten-year time horizon, an additional regular cyclist (i.e., someone cycling most days of the week) was found to generate $798 (₤533) per annum (international dollars). An additional 267 regular cyclists per km were required to break even on the construction of the new separated cycleway. Estimates were particularly sensitive to variations to age, cycling volume and evaluation time horizon. Policymakers planning to invest in cycling infrastructure should consider using these reproducible, order-of-magnitude estimates to complement the more comprehensive transport appraisal and budget allocation processes. This would ensure that, when considering its health-related economic benefits, the investment is justifiable on economic sustainability grounds.

The collaborative pollutants and carbon dioxide emission reduction and cost of ultra-low pollutant emission retrofit in China's cement kiln

Promoting the ultra-low pollutant emission retrofit of the cement industry, as the third largest industry in terms of air pollutants and carbon dioxide (CO2) emissions in China, has become an important part of achieving carbon peaking and carbon neutrality. In this work, the current status of pollutant emission in cement industry and the pollutant emission limit value of ultra-low emission retrofit in typical provinces were analyzed. And, the collaborative air pollutants and CO2 emission reduction potential and cost-benefit were assessed in six types of ultra-low pollution emission retrofit scenarios. The results indicate that the emission reduction of particulate matter (PM)，sulfur dioxide (SO2) and nitrogen oxides (NOx) in six scenarios are 10%–15%, 1%–5% and 26%–64%, respectively. The construction investment of 43.8 billion Yuan is needed to complete the retrofit of production lines when the pollutant emission limit value is set as 10 mg/m3, 35 mg/m3 and 50 mg/m3 for PM, SO2 and NOx, which is 6 times of that when the pollutant emission limit value is set as 10 mg/m3, 50 mg/m3 and 100 mg/m3. However, the cost per unit equivalent of pollutant abatement of the former is only 36% of the latter. The emission reduction potential of CO2 in six scenarios is 0.4%–0.6%, indicating that the ultra-low pollutant emission retrofit in cement kiln has limited effect on CO2 emission reduction potential. Comprehensive analysis of emission reduction potential and cost-benefit, it is more economical and reasonable for China cement kilns to choose the path of ultra-low emission retrofit in scenario 4.

Impact of drought conditions on air pollution over Turkey

AbstractAs a natural disaster, drought affects many sectors such as agriculture and hydrology, as well as having an effect on air quality. In terms of air pollution, drought can reduce wet scavenging of pollutants and change their chemical production/loss and lifetime. This study investigates the relationship between drought events and air pollutants in Turkey. As a drought indicator, the Standardized Precipitation‐Evapotranspiration Index (SPEI)‐1 monthly values for dry (SPEI &lt; −0.99), normal (−0.99 &lt; SPEI &lt; 0.99) and wet (SPEI &lt; 0.99) conditions were used to investigate the changes in PM10, PM2.5, O3 concentration levels. Monthly mean PM10 values of 80 stations for the period 2010–2018, PM2.5 and O3 values of 10 and 12 stations, respectively, were used for the analysis throughout the 2014–2018 period. According to the results, while frequency occurrence of normal conditions decreased in the last period (2010–2018) when compared to the first (1901–2009), drought conditions have significantly increased in each region of Turkey in the last decade. Highest increase in drought events occurred in the inner/southern parts of Turkey. In dry events, while PM10 levels of the stations show above‐normal values, highest regional increase in PM10 was found in the Central Anatolia (CAR), Mediterranean (MeR), Aegean (AR) and Marmara (MR) regions of the country. In fall, high daily temperatures and cloudless days in CAR and MeR regions are seen under deep surface low over continental Europe and surface high over Caspian Sea, which result in severe dryness events and associated high PM10 values in the air quality stations. On the other hand, as a consequence of the expanding Asiatic monsoon low to the eastern part of Turkey, significant amount of moisture is transferred from the Eastern Mediterranean Sea surface to the CAR and MeR regions by southerly flows (wetness SPEI conditions in fall) and cause to appear below‐normal PM10 values in the southern stations.