A Study of Urban Haze and Its Association with Cold Surge and Sea Breeze for Greater Bangkok.

This study deals with haze characteristics under the influence of the cold surge and sea breeze for Greater Bangkok (GBK) in 2017-2022, including haze intensity and duration, meteorological classification for haze, and the potential effects of secondary aerosols and biomass burning. A total of 38 haze episodes and 159 haze days were identified. The episode duration varies from a single day to up to 14 days, suggesting different pathways of its formation and evolution. Short-duration episodes of 1-2 days are the most frequent with 18 episodes, and the frequency of haze episodes decreases as the haze duration increases. The increase in complexity in the formation of relatively longer episodes is suggested by a relatively higher coefficient of variation for PM2.5. Four meteorology-based types of haze episodes were classified. Type I is caused by the arrival of the cold surge in GBK, which leads to the development of stagnant conditions favorable for haze formation. Type II is induced by sea breeze, which leads to the accumulation of air pollutants due to its local recirculation and development of the thermal internal boundary layer. Type III consists of the haze episodes caused by the synergetic effect of the cold surge and sea breeze while Type IV consists of short haze episodes that are not affected by either the cold surge or sea breeze. Type II is the most frequent (15 episodes), while Type III is the most persistent and most polluted haze type. The spread of haze or region of relatively higher aerosol optical depth outside GBK in Type III is potentially due to advection and dispersion, while that in Type IV is due to short 1-day episodes potentially affected by biomass burning. Due to cold surge, the coolest and driest weather condition is found under Type I, while Type II has the most humid condition and highest recirculation factor due to the highest average sea breeze duration and penetration. The precursor ratio method suggests the potential effect of secondary aerosols on 34% of the total haze episodes. Additionally, biomass burning is found to potentially affect half of the total episodes as suggested by the examination of back trajectories and fire hotspots. Based on these results, some policy implications and future work are also suggested.

Evolution of Urban Haze in Greater Bangkok and Association with Local Meteorological and Synoptic Characteristics during Two Recent Haze Episodes.

This present work investigates several local and synoptic meteorological aspects associated with two wintertime haze episodes in Greater Bangkok using observational data, covering synoptic patterns evolution, day-to-day and diurnal variation, dynamic stability, temperature inversion, and back-trajectories. The episodes include an elevated haze event of 16 days (14-29 January 2015) for the first episode and 8 days (19-26 December 2017) for the second episode, together with some days before and after the haze event. Daily PM2.5 was found to be 50 µg m-3 or higher over most of the days during both haze events. These haze events commonly have cold surges as the background synoptic feature to initiate or trigger haze evolution. A cold surge reached the study area before the start of each haze event, causing temperature and relative humidity to drop abruptly initially but then gradually increased as the cold surge weakened or dissipated. Wind speed was relatively high when the cold surge was active. Global radiation was generally modulated by cloud cover, which turns relatively high during each haze event because cold surge induces less cloud. Daytime dynamic stability was generally unstable along the course of each haze event, except being stable at the ending of the second haze event due to a tropical depression. In each haze event, low-level temperature inversion existed, with multiple layers seen in the beginning, effectively suppressing atmospheric dilution. Large-scale subsidence inversion aloft was also persistently present. In both episodes, PM2.5 showed stronger diurnality during the time of elevated haze, as compared to the pre- and post-haze periods. During the first episode, an apparent contrast of PM2.5 diurnality was seen between the first and second parts of the haze event with relatively low afternoon PM2.5 over its first part, but relatively high afternoon PM2.5 over its second part, possibly due to the role of secondary aerosols. PM2.5/PM10 ratio was relatively lower in the first episode because of more impact of biomass burning, which was in general agreement with back-trajectories and active fire hotspots. The second haze event, with little biomass burning in the region, was likely to be caused mainly by local anthropogenic emissions. These findings suggest a need for haze-related policymaking with an integrated approach that accounts for all important emission sectors for both particulate and gaseous precursors of secondary aerosols. Given that cold surges induce an abrupt change in local meteorology, the time window to apply control measures for haze is limited, emphasizing the need for readiness in mitigation responses and early public warning.

Accessing health services in India: experiences of seasonal migrants returning to Nepal.

BACKGROUND: Migration to India is a common livelihood strategy for poor people in remote Western Nepal. To date, little research has explored the degree and nature of healthcare access among Nepali migrant workers in India. This study explores the experiences of returnee Nepali migrants with regard to accessing healthcare and the perspectives of stakeholders in the government, support organizations, and health providers working with migrant workers in India. METHODS: Six focus group discussions (FGDs) and 12 in-depth interviews with returnee migrants were conducted by trained moderators in six districts in Western Nepal in late 2017. A further 12 stakeholders working in the health and education sector were also interviewed. With the consent of the participants, FGDs and interviews were audio-recorded. They were then transcribed and translated into English and the data were analysed thematically. RESULTS: The interviewed returnee migrants worked in 15 of India's 29 states, most as daily-wage labourers. Most were from among the lowest castes so called-Dalits. Most migrants had had difficulty accessing healthcare services in India. The major barriers to access were the lack of insurance, low wages, not having an Indian identification card tied to individual biometrics so called: Aadhaar card. Other barriers were unsupportive employers, discrimination at healthcare facilities and limited information about the locations of healthcare services. CONCLUSIONS: Nepali migrants experience difficulties in accessing healthcare in India. Partnerships between the Nepali and Indian governments, migrant support organizations and relevant stakeholders such as healthcare providers, government agencies and employers should be strengthened so that this vulnerable population can access the healthcare they are entitled to.

Determinants of home delivery in Nepal - A disaggregated analysis of marginalised and non-marginalised women from the 2016 Nepal Demographic and Health Survey.

INTRODUCTION: In Nepal, a substantial proportion of women still deliver their child at home. Disparities have been observed in utilisation of institutional delivery and skilled birth attendant services. We performed a disaggregated analysis among marginalised and non-marginalised women to identify if different factors are associated with home delivery among these groups. MATERIALS AND METHODS: This study used data from the 2016 Nepal Demographic and Health Survey. It involves the analysis of 3,837 women who had experienced at least one live birth in the five years preceding the survey. Women were categorised as marginalised and non-marginalised based on ethnic group. Bivariate and multivariable logistic regression analysis were performed to identify factors associated with home delivery. RESULTS: A higher proportion of marginalised women delivered at home (47%) than non-marginalised women (26%). Compared to non-marginalised women (35%), a larger proportion of marginalised women (64%) felt that it was not necessary to give birth at health facility. The multivariable analysis indicated an independent association of having no or basic education, belonging to middle, poorer and the poorest wealth quintile, residing in Province 2 and not having completed of four antenatal care visits per protocol with home delivery among both marginalised and non-marginalised women. Whereas residing in a rural area, residing in Province 7, and at a distance of >30 minutes to a health facility were factors independently associated with home delivery only among marginalised women. CONCLUSION: We conclude that poor education, poor economic status, non-completion of four ANC visits and belonging to Province 2 particularly determined either group of women to deliver at home, whereas residing in rural areas, living far from health facility, and belonging to Province 7 determined marginalised women to deliver at home. Preventing mothers from delivering at home would thus require focusing on specific geographical areas besides considering wider socio-economic determinants.

Psychological morbidity in Nepali cross-border migrants in India: a community based cross-sectional study.

BACKGROUND: Since Nepali cross-border migrants can freely enter, work and stay in India, they are largely undocumented. The majority is involved in semi-skilled or unskilled jobs with limited labour rights and social security, a fact which predisposes them to psychological distress. We aimed to assess the prevalence of and factors associated with psychological morbidity among Nepali migrants upon their return from India. METHODS: A community based cross-sectional study was conducted in six districts of Nepal between September 2017 and February 2018. A total of 751 participants who had worked at least six months in India and returned to Nepal were interviewed from 24 randomly selected clusters. The General Health Questionnaire (GHQ)-12 was used to measure the psychological morbidity. Data were analysed using Poisson regression analysis. RESULTS: The majority was younger than 35 years (64.1%), male (96.7%), married (81.8%), had at least a primary education (66.6%), and belonged to Dalit, Janajati and religious minorities (53.7%). The prevalence of psychological morbidity was 13.5% (CI: 11.2-16.1%). Participants aged 45 years and above (adjusted prevalence ratio (aPR) = 2.74), from the Terai (aPR = 3.29), a religious minority (aPR = 3.64), who received no sick leave (aPR = 2.4), with existing health problems (aPR = 2.0) and having difficulty in accessing health care (aPR = 1.88) were more likely than others to exhibit a psychological morbidity. CONCLUSION: This study demonstrated that psychological morbidity was prevalent in the study participants and varied significantly with individual characteristics, work conditions and health. Multifaceted approaches including psychological counselling for returnees and protection of labour and health rights in the workplace are recommended to help reduce psychological morbidity.