Spatio-temporal health benefits attributable to PM2.5 reduction in an Indian city.

Fine particulate matter (PM2.5) is linked with a wide spectrum of human health effects and has the highest contribution to total air pollution mortality. This study aims to quantify health benefits of reducing PM2.5 concentration to World Health Organization standard (annual mean = 10 µg m-3) for various health endpoints during 2011-2019 period using AirQ+ and BenMAP-CE software packages. Intraurban assessment in Vellore city, India was done by estimating health benefits at ward level. Both software packages estimated annual average all-cause, ischemic heart disease, stroke, and chronic obstructive pulmonary disease health benefits in the range of 919-945, 175-234, 70-152, and 99-175 cases at city level and 15-16, 3-4, 1-3, and 2-3 cases at ward level, respectively. Sensitivity analysis showed that relative risk had a large influence on health benefit estimates. Present study results will play a crucial role in the future air quality and public health policies of Vellore city.

Mass, composition, and sources of particulate matter in residential and traffic sites of an urban environment.

Present study aims to assess the mass, composition, and sources of PM10 and PM2.5 (particulate matter having aerodynamic diameter less than or equal to 10 and 2.5 µm aerodynamic diameter, respectively) in Vellore city. Seasonal samples collected in traffic and residential sites were analyzed for ions, elements, organic carbon (OC), and elemental carbon (EC). Source apportionment of PM10 and PM2.5 is carried out using Chemical Mass Balance, Unmix, Positive Matrix Factorization and Principal Component Analysis receptor models. Results showed that traffic site had higher annual concentration (PM2.5 = 62 ± 32 and PM10 = 112 ± 23 µg m-3) when compared to residential site (PM2.5 = 54 ± 22 and PM10 = 98 ± 20 µg m-3). Al, Ca, Fe, K, and Mg known to have crustal origin dominated the element composition irrespective of PM size and sampling site. Among ions, SO42- accounted highest in both sites with an average of 70 and 60% to PM2.5 and PM10 ionic mass. Elemental carbon contribution to PM mass was found highest in traffic site (PM2.5 = 17 to 23% and PM10 = 8 to 10%) than residential site (PM2.5 = 9 to 17% and PM10 = 4 to 8%). Elements, ions, OC, and EC accounted 12, 28, 34, and 16% of PM2.5 mass and 12, 21, 20, and 8% of PM10 mass, respectively. Different sources identified by the receptor models are resuspended road dust, crustal material, secondary aerosol, traffic, non-exhaust vehicular emissions, secondary nitrate, construction, cooking, and biomass burning. Since Vellore is aspiring to be a smart city, this study can help the policymakers in effectively curbing PM.

Health effects of particulate matter in major Indian cities.

Background: Particulate matter (PM) is one among the crucial air pollutants and has the potential to cause a wide range of health effects. Indian cities ranked top places in the World Health Organization list of most polluted cities by PM. Objectives: Present study aims to assess the trends, short- and long-term health effects of PM in major Indian cities. Methods: PM-induced hospital admissions and mortality are quantified using AirQ+ software. Results: Annual PM concentration in most of the cities is higher than the National Ambient Air Quality Standards of India. Trend analysis showed peak PM concentration during post-monsoon and winter seasons. The respiratory and cardiovascular hospital admissions in the male (female) population are estimated to be 31,307 (28,009) and 5460 (4882) cases, respectively. PM2.5 has accounted for a total of 1,27,014 deaths in 2017. Conclusion: Cities with high PM concentration and exposed population are more susceptible to mortality and hospital admissions.

Health benefits of achieving fine particulate matter standards in India - A nationwide assessment.

BACKGROUND: Ambient fine particulate matter (PM2.5) is one of the leading risk factors in India. The elevated levels of PM2.5 exposure concentration in India are related to higher premature mortality. However, health benefits or avoidable premature mortality by reducing PM2.5 concentration is uncertain. OBJECTIVES: Here we simulated the health benefits by assuming the achievement of 1) National Ambient Air Quality Standards of India (PM2.5 annual average = 40 µg m-3), 2) National Clean Air Programme policy (30% reduction) and 3) World Health Organization standard (10 µg m-3). METHODOLOGY: Using Environmental Benefits Mapping and Analysis Program - Community Edition (BenMAP-CE), the health benefits are estimated at national, state and district levels for various health endpoints viz., all-cause, ischaemic heart disease (IHD), chronic obstructive pulmonary disease (COPD), lung cancer and stroke. PM2.5 data, concentration-response coefficient, population, and baseline incidence rate are specified as input data in BenMAP-CE. RESULTS: At the national level, all-cause health benefits in three simulations range from 0.79 to 2.1 million cases during 2019. Similarly, IHD, COPD, lung cancer, and stroke related health benefits are in the range of 0.28-0.68, 0.17-0.39, 0.01-0.03, and 0.14-0.34 million cases, respectively. State-level estimates showed that Uttar Pradesh, Bihar, and West Bengal are having maximum health benefits whereas north-eastern states are found with lowest estimates. Districts such as Allahabad, Lucknow, Muzaffarpur, Patna, and Sultanpur are estimated to have highest health benefits. States and districts with higher PM2.5 concentration and exposed population are found with maximum health benefits. Among the three simulations, achievement of the World Health Organization standard resulted in highest estimates. Further, the limitations and sensitivity of input parameters used in this study are discussed in detail. CONCLUSION: Study results highlighted the need for state and district-specific air quality management measures to increase PM2.5 related health benefits.

Application of multiple-path particle dosimetry model for quantifying age specified deposition of particulate matter in human airway.

Particulate matter (PM) is crucial among six criteria air pollutants, and it is frequently associated with human morbidity and mortality. According to the aerodynamic diameter, PM is classified as coarse (PM10) and fine (PM2.5). PM with these smaller sizes can easily enter and get deposited in the human airways. This deposited PM fraction commences the development of respiratory diseases such as asthma, chronic obstructive pulmonary disease, and even cancer. Thus, the quantification of PM deposition and its clearance in the human airway are essential for evaluating health risks. This study aims to investigate the size-segregated PM (PM10, PM2.5, and PM1) deposition in human lungs. Size-segregated PM is collected using the Grimm portable environmental dust monitor during winter season near an arterial road located in Chennai city of Tamil Nadu state, India. Multiple-Path Particle Dosimetry (MPPD) Model version 3.04 is utilized for quantifying PM deposition. In MPPD, airway structures of infants (3 and 28 months), children (3, 8, 9 and 14 years) and adults (18 and 21 years) are considered for the study. The values of PM concentration, body orientation, breathing scenario, tidal volume, pause fraction, inspiration fraction, and breathing frequency are specified in the MPPD for quantifying PM depositions. Results showed that 8-year children and 28 months infant groups are recorded with maximum and minimum size-segregated PM deposition respectively. The coarse particles (PM10) are primarily deposited in the head (55-95%) and tracheobronchial (3-44%) regions whereas fine particles (PM2.5 and PM1) depositions are observed maximum in the head (36-63%) and pulmonary (28.2-52.7%) regions. Except for the adult age group, PM2.5 has the maximum deposition percentage in tracheobronchial and pulmonary regions. In the case of lobar depositions, lower lobes receive maximum deposition (66.4%) than the upper (27.2%) and middle lobes (6.4%). PM2.5 dominated the deposition in all five lobes of infant, children, and adults. The clearance rate of deposited PM is high in the tracheobronchial region whereas it is low in the pulmonary region. This study also concludes that PM2.5 is the important size fraction in lung deposition. Further, the study results can be used for human health risk assessments such as oxidative potential and toxicity of deposited PM.