Air Pollution Data: Collection Methods And Strategies

Air pollution is a global health hazard that contributes to millions of deaths every year. As a result, there has been a push for greater access to air quality data. Collecting air pollution data is essential for raising awareness about the impact of the air we breathe and driving initiatives to improve air quality. This data can be gathered through various methods, including stationary and mobile monitoring systems, and is used to create air quality maps and models that inform research, policy, and community action.

Using vehicles equipped with sensing hardware and data management tools

The vehicles used in this project were Google Street View cars, custom-modified gas-powered vehicles equipped with Aclima's sensing platform and 3D camera equipment. The sensing platform provided sensing hardware, data management capabilities, quality control, and visualization functions. It utilized fast-response laboratory-grade instruments to measure pollution concentrations every second.

Software tools designed by Aclima managed the driving routes, data collection, and processing, enabling large-scale measurements. Scientists from UT Austin designed daily driving plans to ensure that each neighborhood was systematically sampled at different times, providing a comprehensive dataset representative of daytime, weekday air quality.

The cars repeatedly measured pollution levels on every street and highway within a 30 km^2^ area of Oakland, with each street being driven on an average of 30 times over the course of a year. This extensive coverage resulted in one of the largest sets of mobile air pollution measurements ever assembled, offering a detailed understanding of air quality in the region.

The data collected by these vehicles can be used to create pollution maps that emphasize the spatial variability in air pollution levels. These maps can help identify areas with high pollution concentrations and provide valuable insights for improving air quality, developing policies, and protecting public health.

Overall, utilizing vehicles equipped with sensing hardware and data management tools is a powerful approach to collecting air pollution data, enabling large-scale, precise measurements that contribute to a better understanding of air quality and inform effective decision-making.

Analysing satellite-based tools and data

Satellite-based tools and data have become increasingly important in the field of air pollution research. Remote sensing applications have been developed for multiple air pollutants and greenhouse gases, and satellite data is now widely used in decision-making and environmental management activities by public, private, and non-profit organisations.

One of the primary advantages of satellite data is its ability to fill in spatial gaps in ground monitoring. Satellites can provide information on air quality in areas without ground monitors, and their high-altitude deployment enables the measurement of trace gases, aerosols, and greenhouse gases over large areas. For example, in a study of the LA Basin, remote sensing instruments located on Mt. Wilson were able to measure trace gases, aerosols, and greenhouse gases in the whole basin despite being in a single monitoring location.

Satellite data can also be used to estimate emissions, track pollutant plumes, support air quality forecasting, monitor long-term trends, and evaluate air quality model output. For instance, NASA's Terra satellite was used to collect 15 years of air pollution data in Southern California, demonstrating the success of the state's air pollution control programs in reducing fine particle pollution. Satellite data was able to identify specific locations where measured pollutants had decreased, such as concentrations of sulfates in coastal cities and nitrates in transportation corridors in Los Angeles.

In addition to providing information on air pollution levels, satellite data can also be used to develop methods to track wildfires, dust storms, pollen counts, urban green space, nitrogen dioxide concentrations, asthma burdens, tropospheric ozone concentrations, and urban particulate matter mortality. For example, NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) can record the location of fires on the ground by observing unusual hotspots, which may be contributing to air pollution.

However, there are also challenges associated with the use of satellite data for air pollution research. One key barrier is the inherent difficulty in accessing, processing, and interpreting observational data, which requires a degree of technical skill. Additionally, while satellite data can provide valuable information on air pollution at high altitudes, it may not always accurately represent pollution levels on the ground. It is important to compare satellite measurements with ground measurements to determine if the pollution observed in the satellite image is near the surface and affecting air quality.

Utilising government-sponsored platforms and data

Access to air quality data is essential for raising awareness about the impact of air pollution. While less than half of the world's governments produce air quality data, there are a number of government-sponsored platforms that provide open access to air quality data. These platforms are crucial for supporting community-level air quality initiatives, enabling research, improving air quality tools, holding polluters accountable, and facilitating regional cooperation. Here are some examples of how to utilise government-sponsored platforms and data for collecting air pollution data:

USEPA's AirData Platform

The United States Environmental Protection Agency's (USEPA) AirData platform is a prime example of how government-sponsored air quality data can be made accessible to citizens. This platform provides air quality data for the United States, Puerto Rico, and the Virgin Islands. It includes tools such as the AirNow visualisation platform, which offers an interactive map of all air quality monitors in the United States. The AirNow platform also provides comprehensive air quality data, including real-time information during fire events, and historical data for analysing long-term trends.

OpenAQ Platform

OpenAQ is a global platform that shares raw air quality data, enabling the calculation of air pollution levels in specific contexts. It also produces reports on the transparency of national governments in sharing air quality data with the public. OpenAQ's data is valuable for scientific research, policy formulation, and community advocacy. Additionally, OpenAQ's world air quality map features data from over 37,000 air pollution measurement points worldwide, contributing to a more comprehensive understanding of global air pollution trends.

Clarity OpenMap

Clarity, a company specialising in air quality measurement technology, offers the Clarity OpenMap platform. This platform enables users to provide open access to air quality data, supporting community engagement and initiatives to address air pollution. Clarity's Sensing-as-a-Service solution is designed for governments, businesses, and community organisations to collect air pollution measurements and improve air quality management.

Surface Particulate Matter Network (SPARTAN)

SPARTAN is a global network that measures fine particulate concentrations and provides publicly accessible data. This network enhances satellite remote sensing, particularly in regions with limited ground-level air quality information, such as countries in the Global South. By bridging knowledge gaps in global particulate matter (PM2.5) concentrations, SPARTAN contributes to more informed policies and actions to address air pollution.

Air Quality Monitoring Stations

Many governments collect air quality data through networks of monitoring stations equipped with devices and sensors. These stations measure pollutants such as particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and ozone (O3). While higher-income countries tend to have more extensive monitoring networks, lower-income nations often lack the necessary infrastructure or resources for comprehensive monitoring. Efforts are being made to improve access to low-cost air quality sensors and best practices for their utilisation in regions like West Africa through initiatives such as the Sensor Evaluation and Training Centre for West Africa (Afri-SET).

Collecting data from stationary and mobile monitors

Air pollution data collection is critical for monitoring and improving air quality, and there are two primary types of monitoring methods: ambient air quality monitoring and stationary source emissions monitoring.

Stationary Monitors

Stationary monitors are fixed in specific locations and are used to collect data on ambient air quality and emissions from stationary sources such as facilities, manufacturing plants, and processes. The data collected by these monitors helps evaluate the atmosphere's status and compare it to clean air standards and historical data. For example, the Texas Commission on Environmental Quality (TCEQ) operates a network of over 200 stationary monitoring stations, providing data on various pollutants, including ozone, sulfur dioxide, particulate matter, and volatile organic compounds. The placement of these stationary monitors is strategically determined using population trends, emissions inventory data, meteorological data, and existing air monitoring data for the area.

Mobile Monitors

Mobile monitors, on the other hand, offer the advantage of collecting data while on the move. One innovative approach to mobile monitoring is the use of mobile phones equipped with air pollution sensors. For instance, the BROAD Life mobile phone, developed by BROAD Company in China, has built-in sensors that enable direct pollution monitoring. These sensors can measure parameters such as PM2.5 and VOC levels. By connecting these mobile devices to sensors or using Bluetooth pairing, real-time data can be visualised and uploaded to servers for analysis. This technology has the potential to revolutionise personal exposure assessment by providing individuals with the ability to monitor their air quality surroundings.

Data Accessibility

The data collected from both stationary and mobile monitors is essential for various stakeholders, including researchers, communities, and government agencies. Open access to this data enables improvements in public health, raises community awareness about air quality, and empowers communities to hold polluters accountable. Platforms like OpenAQ and Clarity's Sensing-as-a-Service provide open access to air quality data, supporting community-level initiatives and enabling more precise and effective environmental regulations.

Visualising data through maps and graphics

Visualising air pollution data through maps and graphics is a powerful tool for analysis, trend and pattern recognition, and communication. It helps to bring data to life, making it accessible, impactful, and visually compelling.

Maps are particularly useful for displaying air pollution data as they provide a spatial understanding of the information. For instance, NASA's AirData platform provides an interactive map of all air quality monitors in the United States, Puerto Rico, and the Virgin Islands. This allows users to visually assess the distribution of air quality monitors and identify areas with higher or lower monitoring densities. The USEPA's AirNow visualisation platform also offers an interactive approach to viewing air quality and fire information, with tools like the Fire and Smoke Map for fire events.

Maps can also effectively illustrate air pollution levels and their variability. For example, the Environmental Defense Fund's pollution maps of Oakland, California, used colour scales to represent the spatial variability in air pollution levels of surface streets. The darkest red areas on the map indicated the highest levels of black carbon and NO2, with the scales chosen to represent the 90th percentiles of all readings.

Graphics, such as plots and charts, are another valuable tool for visualising air pollution data. NASA's Scientific Visualisation Studio, for instance, uses graphics to reveal data from its pollution-detecting sensors. These visuals help to identify trends and patterns in air pollution levels over time. The AirNow.gov website offers various graphical tools, including a daily air quality tracker for comparing recent AQI values with historical data, and tile plots for observing long-term changes in air quality.

Visualising air pollution data through maps and graphics is essential for raising awareness about air quality issues. Platforms like OpenAQ's world air quality map, with data from over 37,000 measurement points worldwide, provide a global perspective on air pollution. This democratisation of data enables communities, researchers, and policymakers to collaborate and address air pollution and inequality worldwide.

Additionally, integrating socioeconomic data with air quality visuals can provide valuable insights into populations' exposure and vulnerability to pollutants. For example, maps illustrating air pollution death rates by country can highlight the disproportionate impact of air pollution on low-income communities, which often face higher health risks due to proximity to industrial pollution sources and underlying health issues.

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