Air quality is impacting health in many cities in most countries because of particulate pollution, sulfur dioxide, nitrogen dioxide, and ozone. Very small particulates from engine emissions and coal fired electric power plants enter the lungs and pollute the blood of urban residents leading to a burden of disease with more than 3 million premature deaths per year attributed to outdoor air pollution. Welfare losses including premature deaths associated with air pollution were about $5 trillion in 2013. A global transition to electric vehicles, and the generation of electricity without combustion emissions would improve air quality significantly and reduce greenhouse gas emissions. This transition is in progress in many parts of the world with more than 2 million electric vehicles in service in 2017. Electric bus and electric taxi sales are increasing, and many large cities have multiple programs to improve air quality. When health costs are considered, it is very appropriate for communities to take action to improve air quality and health. This work reviews and reports many positive actions that are in progress in larger cities.
Reducing greenhouse gas emissions and improving air quality are significant global challenges. This review addresses air quality, the impact of air pollution on health, and community actions to improve air quality and associated health equity [
Air pollution is a global concern with social costs of the order of $3 trillion/year [
One purpose of this manuscript is to help residents of urban communities in their efforts to understand the air quality where they live, work, and play. Many residents of large cities do not realize that particulates in air have been reported to be the fifth largest overall global risk factor for premature mortality [
Urban cities and metropolitan areas can have air quality management plans (AQMP), which include air quality objectives, monitoring, emission inventory, prediction tools, control strategies, and public participation [
Particulates (PM2.5), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), and sulfur dioxide (SO2) are the most common air pollutants in urban communities [
Pollutant | Primary/ Secondary | Averaging Time | Level | Form | |
---|---|---|---|---|---|
Nitrogen Dioxide (NO2) | Primary | 1 hour | 100 ppb | 98th percentile of 1-hour daily maximum concentrations, averaged over 3 years | |
Primary and Secondary | 1 year | 53 ppb | Annual Mean | ||
Ozone (O3) | Primary and Secondary | 8 hours | 0.070 ppm | Annual fourth-highest daily maximum 8-hour concentration, averaged over 3 years | |
Particle Matter | PM2.5 | Primary | 1 year | 12.0 μg/m3 | Annual mean, averaged over 3 years |
Primary and Secondary | 24 hours | 35 μg/m3 | 98th percentile, averaged over 3 years | ||
PM10 | Primary and Secondary | 24 hours | 150 μg/m3 | Not to be exceeded more than once per year on average over 3 years |
AQI Categories | Health Concern | Ozone (ppm) | PM2.5 (µg/m3) | NO2 (ppb) |
---|---|---|---|---|
Good (up to 50) | Air quality is satisfactory | 0 - 0.054 | 0 - 12.0 | 0 - 53 |
Moderate (51-100) | Air quality is acceptable; however, unusually sensitive people should consider reducing prolonged or heavy exertion. | 0.055 - 0.070 | 12.1 - 35.4 | 54 - 100 |
Unhealthy for Sensitive Groups (101 - 150) | People with heart and lung disease, older adults and children are at a greater risk from exposure to ozone and particulate matter. | 0.071 - 0.085 | 35.5 - 55.4 | 101 - 360 |
Unhealthy (151 - 200) | Everyone may begin to experience some adverse health effects, and those in the sensitive groups may experience more serious health effects. | 0.086 - 0.105 | 55.5 - 150.4 | 361 - 649 |
Very Unhealthy (201 - 300) | Everyone may experience more serious health effects | 0.106 - 0.200 | 150.5 - 250.4 | 650 - 1249 |
Hazardous (301 - 500) | Entire population is more likely to be affected. | - | 250.5 - 500.4 | 1250 - 2049 |
Particulate matter in air is one of the most important air pollutants. The U.S. EPA NAAQS for particulates that are 2.5 micrometers (µm) in equivalent aerodynamic diameter or smaller (PM2.5) are 12 µg/m3 (annual average) and 35 µg/m3 (24-hour average) [
Particulate matter impacts on health depend on the size distribution of the particulates and the chemicals that make up the particulates. The size of particulates from internal combustion vehicle emissions are very small compared to dust from soil. Particulates associated with vehicle emissions range from about 10 nanometers (nm) to 700 nm [
Concentrations of particulate matter in major cities in micrograms per cubic meter are well above the WHO recommended value of 10 µg/m3; annual average values include 170 for Delhi, 66 for Cairo, 55 for Beijing, 19 for Los Angeles, and 13 µg/m3 for Chicago [
The regulatory concentrations of nitrogen dioxide in ambient air are 100 parts per billion (ppb) or 188 µg/m3 (1 hour average value) and 53 ppb or 100 µg/m3 (annual mean value) [
About 58% of nitrogen oxides in urban air are attributed to mobile sources [
Ozone is produced in urban air by photochemical reactions when hydrocarbons and nitrogen oxides are present from vehicle emissions and other sources [
Air quality is impacted by stationary point sources such as coal fired power plants, industrial smoke stacks and mobile sources such as vehicles. Since traffic density varies with location and time of day, there will be variations in air quality that depend on how close vehicle emissions are to the instruments that are making air quality measurements. There are several studies that report air quality data near roads and streets [
Since air pollution includes particulates, sulfur dioxide, nitrogen oxides and ozone epidemiology studies are impacted by more than one pollutant in many cases. It is well known that these pollutants are causally related to cardiovascular disease [
There is evidence that compounds in urban air pollutants move from the lungs to the blood stream and the brain [10, 29]. Decreased cognitive function, autism in children, Parkinson’s disease, and dementia are identified as being more prevalent in large cities because of air pollution [
There are several studies that report an increase in the percent of children with autism because of increased concentrations of air pollutants [
There are significant effects of air pollution due to PM2.5 and ozone on adverse birth outcomes [
Childhood leukemia appears to have an association with air pollution. There may be exposures to air pollution during pregnancy and after birth. Traffic-related air pollution studies have shown an association of traffic density with childhood leukemia [
Multiple sclerosis (MS) is a neurological disorder and chronic inflammatory disease of the central nervous system that has been associated with air pollution [
Recently, the literature related to air pollution and autoimmune disease development has been reviewed for rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), and systematic autoimmune rheumatic diseases (SARDs) [
Data from the Global Burden of Disease Study 2013 has been used to estimate the stroke-related disability adjusted life-years (DALYs) associated with a number of risk factors worldwide from 1990 to 2013 [
The health impacts associated with air pollution may be difficult to measure because of other factors that also affect health such as level of education, psychosocial stressors and quality of medical care [
There are a number of actions that can be taken to improve urban air quality. Since coal combustion is an important source of air pollutants, the transition from coal to wind and solar energy for generation of electricity is a high priority. A number of communities have programs in place with a goal to reduce emissions and air pollutant concentrations. In California, there are ongoing efforts to advance the electrification of transportation with incentives for residents to purchase electric vehicles and programs to encourage solar generation of electricity [
The global issue of greenhouse gas emissions and climate change would benefit if all large cities worked to improve their air quality by transitioning to electric powered transportation and if the electricity was generated without combustion using wind and solar energy, hydro and nuclear power. Some progress is being made as described below.
The U.S. EPA has a research program at the nexus of reducing greenhouse gas emissions and improving air quality [
There are several companies that are making electric buses for use in cities, and the buses are economical for cities to purchase and use [
There are two approaches to charging the batteries on electric buses. One is to have a sufficient charge on the battery to only need to charge them each evening. The other alternative is to have wireless charging at locations where the bus stops along the route. One of the important efforts that is being addressed is the need for international standards for charging buses [
Chicago Transit Authority purchased two electric buses from New Flyer Industries and placed them in service in October 2014 [
London has made progress in its efforts to electrify transportation and reduce air pollution. This includes a transition to electric buses with 51 added in September 2016, and a plan to continue to bring additional electric buses into service until all 300 single-deck buses are electric buses and 3100 double-deckers are hybrid-electric buses [
There has been positive progress in many other communities to transition to electric buses. In China, sales of new electric buses were more than 100,000 in 2016 [
One of the ways to reduce emissions and improve air quality is to transition to electric taxi cabs. A new factory designed to produce 20,000 electric taxi cabs per year for London and other cities is being built in central England [
There is a plan in Beijing, China to convert all of the taxi cabs to electric vehicles. All new taxi cabs are to be electric vehicles with the estimated cost of 67,000 new cabs being about $1.3 billion [
Electric vehicles are being used for taxi cabs in Montreal, Canada, New York City, Austin Texas, Amsterdam, Budapest, Barcelona, Prague, Rome, Stockholm, and many other places [
As the technology for wireless charging develops, it will be possible to have wireless charging while taxi cabs are waiting for customers at locations where there is frequent demand for passengers. Solar panels over these locations can be used to provide shaded charging and electricity. There can be energy storage at these locations also.
Newer ride share services such as Uber and Lyft have the potential to transition to electric vehicles and help with efforts to improve air quality and their image.
There are many additional actions that can be taken to improve air quality and reduce emissions in communities. One approach is to reduce vehicle emissions by promoting walking and bicycle riding. Good sidewalks, bike lanes, and bike paths away from traffic encourage increased walking and cycling. Parking for bicycles is also important. The integration of biking and public transportation to allow bicycles on public transport systems is helpful. Electric bicycles should be promoted by having covered parking and charge stations. Bicycle share programs in which bicycles are available for riding from one place to another can be established in communities [
Low emission zones in cities where vehicles that do not meet emission standards are restricted from entering have been established in many cities [
One significant approach to improving urban air quality is to increase the amount of vegetation in urban areas along streets, in parks, with green roofs, and on balconies [
Los Angeles, California has been working to reduce air pollution for about 50 years [
Public education on the health impacts of air pollution and actions that can be taken is recommended because many people do not understand the impact of air pollution on health [
The Air Quality Index (AQI) is used throughout the world to provide public information on air quality. Values from continuous monitoring are available on the Internet to inform the public about air quality in many locations [
Local air quality can be included in the set of information that is used in making decisions. Senate Bill 352 in the State of California considers air quality in land-use decisions for new schools by not having schools along major roads [
Personal behavior can impact the extent of exposure to air pollution associated with transportation. Some things individuals can do include avoiding rush hour traffic, checking air quality for current and projected readings, exercise in parks rather than along busy roads, consider air quality when deciding where to live, consider air quality and traffic density when making travel plans, filter the air in your home, keep windows closed if the outdoor air is poor, consider air quality for where your children play [
There are four recent publications that address actions that communities and/or governments can take to improve air quality and health [
In the process of searching for good practices to improve urban air quality, it is valuable to understand the community where new practices are to be implemented. Shandas et al. [
A systematic review of 15 recent publications resulted in four strategies to improve urban air quality: general regulations on air emissions, road traffic related interventions, energy generation related interventions, and greenhouse gas emission reduction interventions [
In homes and buildings, high efficiency filters can be used and better air intake locations for large buildings can be selected. Air intakes on roof tops or on sides of the building away from traffic should be considered [
Better understanding of the impact of air pollution on health in urban communities is identified as being important [
Another important community action that may have great impact is to promote a transition to electric vehicles (EVs) by providing incentives to purchase EVs, adding solar powered charging infrastructure in parking lots, and holding community education events that help residents understand the health benefits of reducing emissions. Adding solar panels and charging stations in parking lots has immediate benefits including clean electricity generation, shaded parking and charging infrastructure for EVs [
The transition to electric vehicles may be encouraged by government policy. The United Kingdom, France, India, and Norway have announced plans to end the sale of new gasoline and diesel automobiles at a future date [
In the United States, the U.S. EPA has assisted with community efforts to improve air quality through the Community Air Risk Reduction Initiative (CARRI), the Community Action for a Renewed Environment (CARE) program, and the National Clean Diesel Campaign [
The particulates from vehicle emissions are very small with dimensions from about 10 to 700 nm and they are able to enter the lungs. Some compounds in the particulates enter the blood and are transported to other parts of the body. Air pollution associated with vehicle emissions is a very significant global problem, and annual social costs are of the order of $3 trillion with more than 3 million premature deaths per year associated with outdoor air pollution. The burden of disease on health that is partially attributed to air pollution includes cardiovascular disease, asthma, stroke, chronic obstructive pulmonary disease, lung cancer, dementia, multiple sclerosis, Parkinson’s disease, autism in children, and childhood leukemia. Risks associated with low birth weight and early preterm delivery are greater for those living with higher levels of air pollution.
There are a number of actions that can be taken to improve air quality and health. The electrification of transportation and the transition to the generation of electricity with wind and solar energy are having significant impacts on improving air quality in California and some other parts of the world. Air pollution from coal combustion and industrial sources needs to be reduced in many locations. Electric buses are being purchased and put into service in the United States, Europe, and China. Electric taxi cabs provide another pathway to better air quality and health, and there is progress in their production and sales. More than 200 low emission zones have been established to improve air quality in regions of cities. Fees have been established and implemented to reduce congestion and vehicle emissions in some large cities.
Public education related to air pollution and health is important, and it is part of the process to improve health. Individuals can take action to reduce their exposure to air pollution including monitoring the air quality index, avoiding rush hour exposures, exercising in parks where particulate concentrations are lower, and filtering the air in their homes. Communities can take action to improve the quality of their air through public transport subsidization, promoting electric vehicles, and enhancing charging infrastructure for electric vehicles.
This publication was developed under Assistance Agreement RD83618201 awarded by the U.S. Environmental Protection Agency to Kansas State University. It has not been formally reviewed by EPA. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the Agency. EPA does not endorse any products or services mentioned in this publication.
The authors do not have any conflict of interest.
Erickson, L.E., Griswold, W., Maghirang, R.G. and Urbaszewski, B.P. (2017) Air Quality, Health and Community Action. Journal of Environmental Protection, 8, 1057-1074. https://doi.org/10.4236/jep.2017.810067