Large-scale open burning of straw residues causes seasonal and severe atmospheric pollution in Northeast China. Previous studies focused on the causes or assessment of atmospheric pollution in a single city. However, studies conducted on the interaction range, degree and policy control of pollutant transport on a large scale are still to be performed. In this study, we propose combined control of straw burning by dividing region the straw burning in Northeast China in recent 20 years, determining the transport routes between main cities, and analyzing the interaction characteristics of straw burning under different scenarios. The fire point data suggest that the most intense straw burning years in Northeast China in the past 20 years occurred in the range from 2014 to 2017, mainly after the autumn harvest (October–November) and before spring cultivation (March–April). The burning areas were concentrated in the belt of Shenyang-Changchun-Harbin, the border of the three provinces and Eastern-Inner Mongolia, and the surrounding area of Hegang and Jiamusi City. The lower number of fire points before 2013 indicates that high-intensity burning has not always been the case, while the sharp decline after 2018 is mainly due to scientific control of straw burning and increased comprehensive utilization of straw. Compared with S2, the PM2.5 concentrations increased by 6.2% in S3 and 18.7% in S4, indicating that burning in three or four provinces at the same time will significantly increase air pollution and exert a regional transmission effect. Straw burning in Northeast China is divided into six main regions based on correlation analysis and satellite fire monitoring. Under typical S3, the case analysis results indicate that there is regional transmission interaction between different cities and provinces, focusing on multi-province border cities, and it is affected by Northwest long airflow, and Southeast and Northeast short airflow. These results provide scientific and technological support for implementing the joint prevention and control plan for straw incineration in Northeast China.

As key precursors of tropospheric ozone (O3) pollution, volatile organic compound (VOC) pollution and related studies in China are mainly concentrated in developed regions or metropolises, while there are few studies on VOC pollution in the heavy industrial base in Northeast China. This study conducted a systematic survey of VOCs’ information for the first time in Jilin Province, covering eight prefecture-level cities, ten major industries (e.g., petrochemical, chemical), and 130 major factories, based on cruise monitoring for 2 months. The concentrations and compositions (i.e., 65 species) of VOC were measured in real-time. The emission characteristics of VOC, local source profiles, and the ozone formation potential (OFP) were further analyzed to support O3 pollution control in Northeast China. On the provincial scale, the concentrations of total VOC during the monitoring period ranged from 0.03 to 18321.5 μg/m3, and averaged at 607.9 ± 2051.8 μg/m3. Among the prefecture-level cities, Jilin City had the highest concentration level (1938.0 ± 3811.3 μg/m3) given the largest numbers of petrochemical factories, and the lowest level (85.5 ± 48.9 μg/m3) was found in Liaoyuan City. At the industrial scale, the highest (1915.2 ± 1842.6 μg/m3) was detected in the petrochemical industry with a major species of 1,1,2,2-tetrachloroethane. The lowest VOC emission concentration levels were found in the textile industry (57.8 ± 44.6 μg/m3; major species: xylene/ethylbenzene). Local source profiles in various industries were established, and normalized OFP of corresponding species was calculated, which are important parameters to evaluate the contribution of different VOC sources to O3 pollution. Combined with provincial industrial structure and future planning, we suggest two major industries including the chemical industry and petrochemical industry in Changchun City and Jilin City are prior to being optimized to reduce O3 pollution. This study contributes to the knowledge of the characteristics and source profiles of VOC emissions, providing an important reference for the management or control of O3 pollution in Northeast China.