Altitude-dependent gaseous emissions from freight trucks along the China-Pakistan Economic Corridor in Pakistan

Recent increases in emissions from freight transport have caused strong concerns about air quality in Pakistan,following the rapid development of projects related to the China-Pakistan Economic Corridor(CPEC).This study reported the first measurements of on-road truck emissions in Pakistan and investigated their dependence on altitude along CPEC routes.Emissions from 70 trucks were measured on CPEC highways located in Islamabad(540 m above sea level),Sost(2800 m above sea level),and at the Khunjerab Pass(4693 m above sea level).Calculated emission factors for carbon monoxide,hydrocarbons,and nitrogen oxides from heavy-duty trucks in Islamabad were 12.94±1.46,15.21±1.67,and 10.69±1.34 g km^(-1)(95%confidence level),respectively,for pre-Pak-II trucks,and 12.75±2.80,14.24±3.53,and 10.24±2.34 g km^(-1)(95%confidence level),respectively,for Pak-II trucks,representing 2e20 times higher values than the emission standards in Pakistan and India.An altitude increase of approximately 4000 m,with the associated changes in meteorology and fleet characteristics,induced an average increase of 103.6%,86.3%,124.5%,and 133.6%in the emission factors of carbon monoxide,hydrocarbons,nitrogen oxides,and carbon dioxide,respectively.Moreover,on-road emissions along the CPEC were mainly influenced by truck types.This study will support the budget evaluation of transport emissions from the CPEC trade fleet.

Antagonism between ambient ozone increase and urbanization-oriented population migration on Chinese cardiopulmonary mortality

Everincreasing ambient ozone(O3)pollution in China has been exacerbating cardiopulmonary premature deaths.However,the urban-rural exposure inequity has seldom been explored.Here,we assess populationcale 03 exposure and mortality burdens between 1990 and 2019 based on integrated pollution tracking and epidemiological evidence.We find Chinese population have been suffering from climbing 03 exposure by 4.3±2.8 ppb per decade as a result of rapid urbanization and growing prosperity of socioeconomic activities.Rural residents are broadly exposed to 9.8±4.1 ppb higher ambient O3 than the adjacent urban citizens,and thus urbaniza-tion-oriented migration compromises the exposure-associated mortality on total population.Cardiopulmonary excess premature deaths attributable to longterm 03 exposure,373,500(95%uncertainty interval[U]:240,600-510,900)in 2019,is underestimated in previous studies due to ignorance of cardiovascular causes.Future 03 pollution policy should focus more on rural population who are facing an aggravating threat of mortality risks to ameliorate environmental health injustice.

Synergistic effects of biochar/microbial inoculation on the enhancement of pig manure composting

With the aim to comparatively investigate the effect of the addition of additives such as biochar(BC),microbial inoculation(MI)and biochar/microbial inoculation(BCMI)on composting enhancement,nitrogen conservation,greenhouse gas emissions,the quality improvement of pig manure compost were comparatively investigated in a 42-day aerobic pig manure composting experiment.The results showed that the duration of the thermophilic stage,the degradation of organic matter and the detoxification of the compost were enhanced in the BC,MI and BCMI treatments compared with those in the control(without additive).Moreover,the content of total Kjeldahl nitrogen in the BC,MI and BCMI treatments was increased by 38.1,48.9 and 59.0%,respectively,through the reduction of NH_(3) volatilization and N_(2)O production,which were higher than those of the control(31.8%).A reduction in CH_(4) release during composting was not observed with the MI and BCMI treatments.Following 42 days of composting,the final product of the three treatments exhibited acceptable potential for use as a fertilizer in agriculture;the BCMI treatment showed an especially synergistic effect on pig manure composting enhancement.