Air Pollution, Air Quality, and Climate Change

Author(s):  
Alan H. Lockwood

The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content may blunt this effect in some regions. Higher levels of natural volatile organic compounds (VOCs), such as terpenes from plants, are likely to act synergistically with anthropogenic VOCs to favor ozone production. Droughts increase wildfire risks that produce particulate pollution and carbon monoxide, a VOC involved in ozone production. Some models predict increased ozone concentrations in many urban settings. Future revisions of National Ambient Air Quality Standards, a process driven by politics and science, should consider these effects.

2016 ◽  
Author(s):  
Wan Jiao ◽  
Gayle Hagler ◽  
Ronald Williams ◽  
Robert Sharpe ◽  
Ryan Brown ◽  
...  

Abstract. Advances in air pollution sensor technology have enabled the development of small and low cost systems to measure outdoor air pollution. The deployment of a large number of sensors across a small geographic area would have potential benefits to supplement traditional monitoring networks with additional geographic and temporal measurement resolution, if the data quality were sufficient. To understand the capability of emerging air sensor technology, the Community Air Sensor Network (CAIRSENSE) project deployed low cost, continuous and commercially-available air pollution sensors at a regulatory air monitoring site and as a local sensor network over a surrounding ~ 2 km area in Southeastern U.S. Co-location of sensors measuring oxides of nitrogen, ozone, carbon monoxide, sulfur dioxide, and particles revealed highly variable performance, both in terms of comparison to a reference monitor as well as whether multiple identical sensors reproduced the same signal. Multiple ozone, nitrogen dioxide, and carbon monoxide sensors revealed low to very high correlation with a reference monitor, with Pearson sample correlation coefficient (r) ranging from 0.39 to 0.97, −0.25 to 0.76, −0.40 to 0.82, respectively. The only sulfur dioxide sensor tested revealed no correlation (r  0.5), step-wise multiple linear regression was performed to determine if ambient temperature, relative humidity (RH), or age of the sensor in sampling days could be used in a correction algorithm to improve the agreement. Maximum improvement in agreement with a reference, incorporating all factors, was observed for an NO2 sensor (multiple correlation coefficient R2adj-orig = 0.57, R2adj-final = 0.81); however, other sensors showed no apparent improvement in agreement. A four-node sensor network was successfully able to capture ozone (2 nodes) and PM (4 nodes) data for an 8 month period of time and show expected diurnal concentration patterns, as well as potential ozone titration due to near-by traffic emissions. Overall, this study demonstrates a straightforward methodology for establishing low-cost air quality sensor performance in a real-world setting and demonstrates the feasibility of deploying a local sensor network to measure ambient air quality trends.


2020 ◽  
Author(s):  
Pierre Sicard ◽  
Evgenios Agathokleous ◽  
Alessandra De Marco ◽  
Elena Paoletti ◽  
Vicent Calatayud

Abstract Background - The paper presents an overview of air quality in the 27 member countries of the European Union (EU) and the United Kingdom (previous EU-28), from 2000 to 2017. We reviewed the progress made towards meeting the air quality standards established by the EU Ambient Air Quality Directives (Directive 2008/50/EC) and the World Health Organization (WHO) Air Quality Guidelines by estimating the trends (Mann-Kendal test) in national emissions of main air pollutants, urban population exposure to air pollution, and in mortality related to exposure to ambient fine particles (PM2.5) and tropospheric ozone (O3). Results - Despite significant reductions of emissions (e.g. sulfur oxides: ~80%, nitrogen oxides: ~46%, non-methane volatile organic compounds: ~44%, particulate matters with a diameter lower than 2.5µm and 10µm: ~30%), the EU-28 urban population was exposed to PM2.5 and O3 levels widely exceeding the WHO limit values for the protection of human health. Between 2000 and 2017, the annual PM2.5-related number of deaths decreased (- 4.85 per 106 inhabitants) in line with a reduction of PM2.5 levels observed at urban air quality monitoring stations. The rising O3 levels became a major public health issue in the EU-28 cities where the annual O3-related number of premature deaths increased (+ 0.55 deaths per 106 inhabitants). Conclusions - To achieve the objectives of the Ambient Air Quality Directives and mitigate air pollution impacts, actions need to be urgently taken at all governance levels. In this context, greening and re‐naturing cities can help meet air quality standards, but also answer to social needs, as recently highlighted by the COVID-19 lockdowns.


2021 ◽  
Author(s):  
Maayan Yitshak Sade ◽  
Liuhua Shi ◽  
Elena Colicino ◽  
Heresh Amini ◽  
Joel Schwartz ◽  
...  

Objective: Type 2 diabetes mellitus is a major public health concern. We assessed the association between air pollution and first documented diabetes occurrence in a national U.S. cohort of Medicare enrollees to estimate incidence risk. Research design and methods: We included all Medicare enrollees 65 years and older in the fee-for-service program, part A and part B, in the contiguous United States (2000-2016). Participants were followed annually until the first recorded diabetes diagnosis, end of enrollment, or death. We obtained air pollution annual estimates of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) exposures from highly spatiotemporally resolved prediction models. We assessed the simultaneous effect of the pollutants on diabetes incidence using Poisson survival analysis with adjustment for temporal and spatial confounders. We repeated the models in data restricted to ZIP codes with air pollution levels not exceeding the ambient air quality standards during the study period. Results: We have included 264,869,458 person-years of 41,780,637 people. We observed nonlinear associations between the three pollutants and diabetes, with larger risks at lower levels for PM2.5 and O3. When restricting the data to lower air pollution levels, an increased risk for diabetes (Incidence Rate Ratio [95% Confidence Interval] was associated with interquartile range (IQR) increases in PM2.5 (1.048 [1.045;1.051]), O3 (1.016 [1.014;1.18]), and NO2 (1.040 [1.037; 1.043]). Conclusion: We found increased diabetes risk associated with air pollution exposures. The observed effects remained in exposure levels below the national ambient air quality standards in the U.S.


2014 ◽  
Vol 2 ◽  
pp. 35-41 ◽  
Author(s):  
N.B. Dhital ◽  
W.T. Hung ◽  
R.M. Byanju

Owing to widespread road widening activities and the growing vehicular traffic, air quality of Kathmandu Valley has been a matter of grave concern. In this study, we monitored air quality inside public vehicles of Kathmandu Valley which would help assess the exposure of public transport users to air pollution. Problem of particulate pollution, especially PM10, was found severe inside the buses. Carbon monoxide and total volatile organic compounds were mostly within acceptable levels but benzene exceeded guidelines in few samples. Benzene, toluene, ethylbenzene and xylene (BTEX) were dominant among all detected volatile organic compounds. There was high degree of correlation among BTEX. Similarly, significant correlation was found between carbon monoxide and total volatile organic compounds. PM10 and PM2.5 were also significantly correlated suggesting common source of emission. Gaseous pollutants had significant negative correlation with traffic speed suggesting that traffic congestion (responsible for low traffic speed and high traffic density) is causing higher emission.


1996 ◽  
Vol 3 (1) ◽  
pp. 29-39 ◽  
Author(s):  
TEE L Guidotti

This second of two parts continues with the development of a framework for understanding air quality issues and their relationship to human health. Recognized health effects associated with air pollution are described and current controversies regarding ozone and PM10are briefly outlined. Epidemiological methods of investigating air quality effects are discussed, comparing recent landmark studies in Canada. Comparative prevalence studies do not reflect the state of the art in air pollution epidemiology but are frequently cited and conducted in Canada as if they were definitive. The implications of setting air quality standards and objectives on this basis or to meet arbitrary levels of risk of health effects are examined. The current state of the art does not support risk-based air quality standards. A policy of continuous improvement is most protective of both human health and the environment.


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