Air quality impacts of the low emission zone policy in Haifa

摘要

This study analyzes the performance of the first year of implementation of the low emission zone policy in Haifa (February 2018-January 2019), looking at its effects on ambient black carbon, NOX and particulate matter concentrations. Statistically significant reduction of black carbon and NOX concentrations, and a decline in the black carbon fraction in PM1 was observed at the Atzmaut monitoring station, suggesting that the measures taken to reduce air pollution as part of the Haifa low emission zone were successful. Regarding NOX concentrations, the reported results for Haifa after the first year of the low emission zone policy (12.9%) are better than those previously reported in Western Europe (mostly 0-7%). As for black carbon, the concentration reduction (10.6%) is less than that reported in Western Europe (mostly 14-60%). Yet, traffic volumes in general and, the fraction of diesel vehicles in the total fleet in particular, differ considerably among different cities. Comparison of trends of black carbon and NOX showed good correlations on both daily (0.96) and half-hourly (0.92) basis. Trends of black carbon, benzene, PM2.5 and PM1 agreed relatively nicely on a daily basis (correlation coefficients of 0.84, 0.52 and 0.54, respectively) but only partially on a half-hourly basis (correlation coefficients of 0.52, 0.31 and 0.37, respectively). Thus, in spite of the LEZ starting only one year ago, observations suggest that it has considerable effect of the air quality in Haifa.