An air pollutant emission inventory of non-road machineries for the Yangtze River Delta (YRD) region was developed, based on local surveys and relative indicator predictions for cities in the region. Population, fuel consumption, and air pollutant emissions of non-road machineries were predicted for the period 2005 to 2025. The population of non-road machineries in the YRD region in 2014 was 8.23×106 units, diesel consumption was about 9.95×106 t, and SO2, NOx, CO, VOCs, PM10, and PM2.5 emissions were 5.5×103, 4.9×105, 7.6×105, 1.1×105, 2.9×104, and 2.7×104 t, respectively. Agricultural machineries accounted for 93% of the total population, with their CO and VOC emissions contributing 88% and 77% of respective totals. Construction machineries contributed 49% and 35% of NOx and PM2.5 emissions. Air pollutant emissions from non-road machineries were mainly concentrated in the middle and northern cities of the YRD region. During the period 2005-2014, the growth rates of population, fuel consumption, and air pollutant emissions of non-road machineries in the YRD region were relatively high. It is estimated that growth will be slowing down in 2020 and 2025. Diesel consumption will increase by 2% and 8% in 2020 and 2025, respectively, compared with 2014 levels. By 2020, SO2, NOx, CO, VOCs, PM10, and PM2.5 emissions will decrease by 97%, 10%, 3%, 10%, 11%, and 11%, respectively; by 2025, these decreases will reach 97%, 16%, 3%, 15%, 21%, and 21%, respectively. It is expected that air pollutant emissions from non-road machineries will continue to decline in future. However, the decreasing trend of NOx, VOCs, and PM2.5 emissions from motor vehicles reached 22%, 50%, and 48%, much greater than that of non-road machinery. The emission contributions of non-road machinery will become increasingly significant in future. It is necessary to accelerate the scrappage of old machinery and to further promote emission standards for new machinery to reduce emissions from non-road machineries.
Keywords: air pollution; emission inventory; emission projection; non-road machineries; the Yangtze River Delta (YRD) region.