Impact assessment of a raw coal ban on maternal and child health outcomes in Ulaanbaatar: a protocol for an interrupted time series study.

INTRODUCTION: Despite a decade of policy actions, Ulaanbaatar's residents continue to be exposed to extreme levels of air pollution, a major public health concern, especially for vulnerable populations such as pregnant women and children. In May 2019, the Mongolian government implemented a raw coal ban (RCB), prohibiting distribution and use of raw coal in households and small businesses in Ulaanbaatar. Here, we present the protocol for an interrupted time series (ITS; a strong quasi-experimental study design for public health interventions) that aims to assess the effectiveness of this coal ban policy on environmental (air quality) and health (maternal and child) outcomes. METHODS AND ANALYSIS: Routinely collected data on pregnancy and child respiratory health outcomes between 2016 and 2022 in Ulaanbaatar will be collected retrospectively from the four main hospitals providing maternal and/or paediatric care as well as the National Statistics Office. Hospital admissions data for childhood diarrhoea, an unrelated outcome to air pollution exposure, will be collected to control for unknown or unmeasured coinciding events. Retrospective air pollution data will be collected from the district weather stations and the US Embassy. An ITS analysis will be conducted to determine the RCB intervention impact on these outcomes. Prior to the ITS, we have proposed an impact model based on a framework of five key factors, which were identified through literature search and qualitative research to potentially influence the intervention impact assessment. ETHICS AND DISSEMINATION: Ethical approval has been obtained via the Ministry of Health, Mongolia (No.445) and University of Birmingham (ERN_21-1403). To inform relevant stakeholders of our findings, key results will be disseminated on both (inter)national and population levels through publications, scientific conferences and community briefings. These findings are aimed to provide evidence for decision-making in coal pollution mitigation strategies in Mongolia and similar settings throughout the world.

Carbon monoxide levels in households using coal-briquette fuelled stoves exceed WHO air quality guidelines in Ulaanbaatar, Mongolia.

In 2019, a domestic raw coal ban (RCB) was introduced in Ulaanbaatar, Mongolia. Coal-briquettes have since been promoted in Ger district households, however implications for carbon monoxide (CO) exposure remains uncertain. We obtained 48-hour indoor CO concentrations in 23 Ger district households and compared these to 10 raw-coal households. Information on household characteristics, fuel use behaviour and stove venting practices was collected by survey. Mean 48-hour CO concentrations in coal-briquette households was 6.1 ppm (range 1.5-35.8 ppm) with no signfiicant differences by household, stove or venting factors. Peak time-weighted average CO concentrations exceeded WHO Indoor Air Quality guidelines in 9 (39%) households; with all surpassing the 8-hour guideline (>8.6 ppm); 3(13%) the 24-hour guideline (>6 ppm) and 2(9%) the 1-hour guideline (>30 ppm). Median CO levels were significantly lower in coal-briquette compared to raw coal households (p = 0.049). Indoor CO reduction was associated with RCB implementation although hazardous levels persist in this setting.

Winter Air Pollution from Domestic Coal Fired Heating in Ulaanbaatar, Mongolia, Is Strongly Associated with a Major Seasonal Cyclic Decrease in Successful Fecundity.

Pollution of the environment is increasing and threatens the health and wellbeing of adults and children around the globe. The impact of air pollution on pulmonary and cardiovascular disease has been well documented, but it also has a deleterious effect on reproductive health. Ulaanbaatar, the capital city of Mongolia, has one of the highest levels of air pollution in the world. During the extreme winters when temperatures routinely fall below -20 °C the level of air pollution can reach 80 times the WHO recommended safe levels. Heating mainly comes from coal, which is burned both in power stations, and in stoves in the traditional Ger housing. We studied the impact of air pollution on conception rates and birth outcomes in Ulaanbaatar using a retrospective analysis of health data collected from the Urguu Maternity hospital in Ulaanbaatar, Mongolia. Daily levels of SO2, NO2, PM10, and PM2.5 were collected from the government Air Quality Monitoring Stations in Ulaanbaatar for the same period as the study. In January, the month of highest pollution, there is a 3.2-fold decrease in conceptions that lead to the successfully delivered infants compared to October. The seasonal variations in conceptions resulting in live births in this study in Ulaanbaatar are shown to be 2.03 ± 0.20 (10-sigma) times greater than those in the Denmark/North America study of Wesselink et al., 2020. The two obvious differences between Ulaanbaatar and Europe/North America are pollution and temperature both of which are extreme in Ulaanbaatar. The extreme low temperature is mitigated by burning coal, which is the main source of domestic heat especially in the ger districts. This drives the level of pollution so the two are inextricably linked. Infants conceived in the months of June-October had the greatest cumulative PM2.5 pollution exposure over total gestation, yet these were also the pregnancies with the lowest PM2.5 exposure for the month of conception and three months prior to conception. The delivered-infant conception rate shows a markedly negative association with exposure to PM2.5 prior to and during the first month of pregnancy. This overall reduction in fecundity of the population of Ulaanbaatar is therefore a preventable health risk. It is of great consequence that the air pollution in Ulaanbaatar affects health over an entire lifespan including reproductive health. This could be remedied with a clean source of heating.