Summer and Fall 2010

vary depending on the time of year (figure 3.15). Open burning, mostly from crop residues from the rice harvest, is much more prevalent in the fall after the harvest season. Thus, the share of PM2.5 concentration in fall 2010 was much higher than in summer 2010.

Knowing the sources has allowed the government to launch a program to tackle air pollution stemming from agricultural waste burning, which included establishment of a market for crop residues and awareness programs about the dangers of burning crop residues and alternative options. For a more detailed description of the “black cloud” phenomenon and policies to tackle it, see box 3.14.

Despite the importance of source identification analyses—such as source apportionment analyses and emissions inventory work—only a few cities in the Middle East and North Africa have performed such studies, and openly available information on the sources of pollutants is sparse for the region’s cities and economies. In a global database containing source apportionment studies (Karagulian et al. 2015), only seven studies for four cities in the Middle East and North Africa were available, some dating back to the early 2000s.20 In the past few years, not many more have been added to that list. By comparison, in the European Union (EU), North America, and some higher-income Asian countries, such source studies are frequently carried out, and time series information is often available. This lack of sampling, testing, and results reporting in the Middle East and North Africa leads to a lack of

FIGURE 3.15

Decomposition of PM2.5 Sources in Greater Cairo, Summer and Fall 2010

Fall, 2010

Summer, 2010

0 10 20 30 40 50 60 70 80 90 100 Share of contribution to PM2.5 concentrations (%) Geological material Ammonium Motor vehicles Other Open burning

Source: Heger et al. 2019, based on World Bank 2013. Note: Geological material includes sand and soil dust either occurring naturally (for example, sand from the desert) or stemming from human activity (for example, road dust, sand from construction activity). Particulate matter (PM) pollution from ammonium can occur through industrial but also agricultural activities (for example, fertilizer). PM2.5 is PM that measures 2.5 microns or less in diameter.

understanding of the source profile of PM air pollution for most of the region’s economies and cities.

The source information is likely the single most significant piece of missing evidence needed for policy making on air pollution management in the Middle East and North Africa. To help policy makers obtain accurate source attribution, further studies and more detailed data are required (Karagulian et al. 2015). To effectively and efficiently tackle the air pollution challenges that so many of the region’s cities face, knowledge about where pollution comes from is of paramount importance and cannot be based on globally modeled information. It is strongly recommended that the region’s economies and cities invest in carrying out source identification studies to understand their individual source profiles.

Models for Emulation

Regular measurement and reporting of air pollution sources has been adopted in the United States and Western Europe to support policy makers in their decision-making processes. Such measurement and reporting are highly encouraged for Middle East and North Africa economies. Source apportionment can be accomplished through three main approaches: emissions inventories, source-oriented models, and receptor-oriented models.

The US Environmental Protection Agency (EPA) provides a comprehensive, detailed estimate of air pollutant emissions—the National Emissions Inventory (NEI)—every three years. It collects data from state, local, and tribal air agencies and blends that information with data from other sources. The European Environment Agency (EEA) disseminates annual emissions inventories with air emissions accounts provided by each member state. This agency reports the amount of air pollutant and GHGs emissions broken down by 64 industries plus households. It also releases data on intensity ratios—emissions per unit of value added or production output.

For the EU and associated states, more detailed analyses of pollution sources are easily accessible and updated annually. For example, figure 3.16 shows sector-contribution shares of anthropogenic activities for various air pollutant emissions in the European Economic Area. For PM2.5 emissions (sixth bar), the largest sector contribution came from the “commercial, institutional, and households” sector, mainly consisting of household emissions (95 percent) from sources such as wood combustion for heating. Industrial processes, when including energy production and its use in industries, contributed around 25 percent of the PM2.5 pollution. Close behind as a source of PM2.5 air pollution is the road transportation sector. In the Middle East and