The effects of 3 environmental risks on mortality disparities across Mexican communities

Socioeconomic driving forces behind air polluting emissions in Mexico

Air pollution is one of the most severe environmental problems that Mexico is currently facing. The objective of this paper is to quantify the most relevant socioeconomic driving forces behind air polluting emissions and, more specifically, 7 local pollutants in Mexico. We do so in a multilevel version of the Stochastic Impacts by Regression on Population, Affluence and Technology (STIRPAT) model that accounts for the spatial heterogeneity at the municipal level across the country. The results show that the most relevant variables to determine the emissions of atmospheric pollutants are the population, the harvested area and the number of cars, while technological development helps to mitigate such emissions. The ecological elasticities are, in all cases, smaller than one. Our purpose is to provide quantitative information about these socioeconomic driving forces of air deterioration as a basis to establish some recommendations for environmental policy decision-making.

Air pollution attributed disease burden and economic growth in India: Estimating trends and inequality between states

Background

Air pollution is one of the major contributors to the disease burden in India after malnutrition. We examined the relation, and state-wise disparities in air pollution attributed to disease burden (APADB) concerning gross state domestic product (GSDP) and growth in motor vehicles in India.

Methods

We retrieved disability-adjusted life year (DALY) estimates for India due to air pollution from the Global Burden of Disease Studies, injuries, and Risk Factors Study (GBD). We examined the association between APADB with GSDP and the growth in the number of registered motor vehicles in India during the 2011 to 2019 period. Concentration indices and Lorenz curves were used to explore the variation in APADB across individual states.

Findings

Except for a few states, APADB is inversely proportional to GSDP. Growth in motor vehicles was also negatively correlated with the APADB in n=19 states. The concentration index explained a 47% inequality in APADB between individual states and exhibited a decline (45%) during 2019 compared to 2011. The unevenness in APADB among Indian states is evident from the analysis as the states occupying the 6^th or 7^th decile and above in terms of GDP, urbanization and population contribute more than 60 per cent of the total APADB.

Interpretation

The APADB is inversely correlated with GSDP for most of the states, and the negative correlations were conspicuous when APADB per 100,000 population was analysed. The concentration index and Lorenz revealed the presence of APADB inequality between states in terms of GSDP, population, urbanisation, and total factories.

Funding

Not applicable.

Air Pollution and Environmental Justice in Latin America: Where Are We and How Can We Move Forward?

PURPOSE OF REVIEW

Air pollution in Latin America is a major environmental threat, yet few studies have focused on aspects of environmental justice with regard to air pollution in the region. We examined the scientific literature and described whether and how this issue has been addressed, identify possible gaps in knowledge, and offer suggestions for future research to contribute to policies that seek greater equity concerning air pollution impacts in Latin America.

RECENT FINDINGS

There is a limited literature that has addressed issues of environmental justice or environmental health inequalities about air pollution in Latin America, with studies concentrated in Brazil, Mexico, and Chile. Studies that examined disparities in exposure to air pollution found a clear pattern of higher exposure in socially deprived areas. Studies that examined disparities in health impacts associated with air pollution have mixed results, but many found a clear modification of effect with those in the lower socioeconomic groups presenting greater effects. Despite Latin America's colonial and slavery history, no studies have considered ethnicity or minority populations. The literature shows that health risks (exposure and susceptibility) associated with air pollution are unevenly distributed among Latin American populations. Methodological approaches varied and can be improved in future studies, especially for exposure assessment to air pollution, as well as for assigning socioeconomic position to individuals. Using smaller geographic units and spatial regression techniques will allow a reduction in measurement error. Attempts should be made to include both individual and contextual socioeconomic indicators in the analysis. Better quality information will help understand these differential exposures and effects and provide inputs to policies to tackle these inequalities.

Mortality Benefits and Control Costs of Improving Air Quality in Mexico City: The Case of Heavy Duty Diesel Vehicles

Diesel vehicles are significant contributors to air pollution in Mexico City. We estimate the costs and mortality benefits of retrofitting heavy-duty vehicles with particulate filters and oxidation catalysts. The feasibility and cost-effectiveness of controls differ by vehicle model-year and type. We evaluate 1985 to 2014 model-year vehicles from 10 vehicle classes and five model-year groups. Our analysis shows that retrofitting all vehicles with the control that maximizes expected net benefits for that vehicle type and model-year group has the potential to reduce emissions of primary fine particles (PM_2.5 ) by 950 metric tons/year; cut the population-weighted annual mean concentration of PM_2.5 in Mexico City by 0.90 µg/m³ ; reduce the annual number of deaths attributable to air pollution by over 80; and generate expected annual health benefits of close to 250 million US$. These benefits outweigh expected costs of 92 million US$ per year. Diesel retrofits are but one step that should viewed in the context of other efforts--such as development of an integrated public transportation system, promotion of the rational use of cars, reduction of emissions from industrial sources and fires, and redesign of the Mexico City Metropolitan Area to reduce urban sprawl--that must be analyzed and implemented to substantially control air pollution and protect public health. Even if considering other potential public health interventions, which would offer greater benefits at the same or lower costs, only by conducting, promoting, and publishing this sort of analyses, we can make strides to improve public health cost-effectively.

Health Effects of Ambient Air Pollution in Developing Countries

The deleterious effects of ambient air pollution on human health have been consistently documented by many epidemiologic studies worldwide, and it has been calculated that globally at least seven million deaths are annually attributable to the effects of air pollution. The major air pollutants emitted into the atmosphere by a number of natural processes and human activities include nitrogen oxides, volatile organic compounds, and particulate matter. In addition to the poor ambient air quality, there is increasing evidence that indoor air pollution also poses a serious threat to human health, especially in low-income countries that still use biomass fuels as an energy resource. This review summarizes the current knowledge on ambient air pollution in financially deprived populations.

Household Fuel Use and Cardiovascular Disease Mortality: Golestan Cohort Study

BACKGROUND

Household air pollution is the third largest risk factor for global disease burden, but direct links with cardiovascular disease mortality are limited. This study aimed to evaluate the relationship between household fuel use and cardiovascular disease mortality.

METHODS AND RESULTS

The Golestan Cohort Study in northeastern Iran enrolled 50 045 individuals 40 to 75 years of age between 2004 and 2008 and collected data on lifetime household fuel use and other baseline exposures. Participants were followed up through 2012 with a 99% successful follow-up rate. Cox proportional hazards models were fitted to calculate hazard ratios for associations between pehen (local dung), wood, kerosene/diesel, or natural gas burning for cooking and heating and all-cause and cause-specific mortality, with adjustment for lifetime exposure to each of these fuels and potential confounders. A total of 3073 participants (6%) died during follow-up; 78% of these deaths were attributable to noncommunicable diseases, including cardiovascular, oncological, and respiratory illnesses. Adjusted 10-year hazard ratios from kerosene/diesel burning were 1.06 (95% confidence interval, 1.02-1.10) and 1.11 (95% confidence interval, 1.06-1.17) for all-cause and cardiovascular mortality, respectively. Subtype-specific analyses revealed a significant increase in ischemic heart disease (10-year hazard ratio, 1.14; 95% confidence interval, 1.06-1.21) and a trend toward cerebrovascular accident (10-year hazard ratio, 1.08; 95% confidence interval, 0.99-1.17) mortality. Stratification by sex revealed a potential signal for increased risk for all-cause and cardiovascular disease mortality among women compared with men, with similar risk for ischemic heart disease mortality.

CONCLUSIONS

Household exposure to high-pollution fuels was associated with increased risk for all-cause and cardiovascular disease mortality. Replicating these results worldwide would support efforts to reduce such exposures.

Geographical Inequalities and Social and Environmental Risk Factors for Under-Five Mortality in Ghana in 2000 and 2010: Bayesian Spatial Analysis of Census Data

BACKGROUND

Under-five mortality is declining in Ghana and many other countries. Very few studies have measured under-five mortality-and its social and environmental risk factors-at fine spatial resolutions, which is relevant for policy purposes. Our aim was to estimate under-five mortality and its social and environmental risk factors at the district level in Ghana.

METHODS AND FINDINGS

We used 10% random samples of Ghana's 2000 and 2010 National Population and Housing Censuses. We applied indirect demographic methods and a Bayesian spatial model to the information on total number of children ever born and children surviving to estimate under-five mortality (probability of dying by 5 y of age, 5q0) for each of Ghana's 110 districts. We also used the census data to estimate the distributions of households or persons in each district in terms of fuel used for cooking, sanitation facility, drinking water source, and parental education. Median district 5q0 declined from 99 deaths per 1,000 live births in 2000 to 70 in 2010. The decline ranged from <5% in some northern districts, where 5q0 had been higher in 2000, to >40% in southern districts, where it had been lower in 2000, exacerbating existing inequalities. Primary education increased in men and women, and more households had access to improved water and sanitation and cleaner cooking fuels. Higher use of liquefied petroleum gas for cooking was associated with lower 5q0 in multivariate analysis.

CONCLUSIONS

Under-five mortality has declined in all of Ghana's districts, but the cross-district inequality in mortality has increased. There is a need for additional data, including on healthcare, and additional environmental and socioeconomic measurements, to understand the reasons for the variations in mortality levels and trends.

Geographical and socioeconomic inequalities in women and children's nutritional status in Pakistan in 2011: an analysis of data from a nationally representative survey

BACKGROUND

Pakistan has one of the highest levels of child and maternal undernutrition worldwide, but little information about geographical and socioeconomic inequalities is available. We aimed to analyse anthropometric indicators for childhood and maternal nutrition at a district level in Pakistan and assess the association of nutritional status with food security and maternal and household socioeconomic factors.

METHODS

We used data from the 2011 Pakistan National Nutrition Survey, which included anthropometric measurements for 33 638 children younger than 5 years and 24 826 women of childbearing age. We estimated the prevalences of stunting, wasting, and underweight among children and of underweight, overweight, and obesity in women for all 143 districts of Pakistan using a Bayesian spatial technique. We used a mixed-effect linear model to analyse the association of nutritional status with individual and household sociodemographic factors and food security.

FINDINGS

Stunting prevalence in Pakistan's districts ranged between 22% (95% credible interval 19-26) and 76% (69-83); the lowest figures for wasting and underweight were both less than 2·5% and the highest were 42% (34-50) for wasting and 54% (49-59) for underweight. In 106 districts, more women were overweight than were underweight; in 49 of these districts more women were obese than were underweight. Children were better nourished if their mothers were taller or had higher weight, if they lived in wealthier households, and if their mothers had 10 or more years of education. Severe food insecurity was associated with worse nutritional outcomes for both children and women.

INTERPRETATION

We noted large social and geographical inequalities in child and maternal nutrition in Pakistan, masked by national and provincial averages. Pakistan is also beginning to face the concurrent challenge of high burden of childhood undernutrition and overweight and obesity among women of reproductive age. Planning, implementation, and evaluation of programmes for food and nutrition should be based on district-level needs and outcomes.

FUNDING

Bill & Melinda Gates Foundation, Grand Challenges Canada, UK Medical Research Council.

Exploring potential sources of differential vulnerability and susceptibility in risk from environmental hazards to expand the scope of risk assessment

Genetic factors, other exposures, individual disease states and allostatic load, psychosocial stress, and socioeconomic position all have the potential to modify the response to environmental exposures. Moreover, many of these modifiers covary with the exposure, leading to much higher risks in some subgroups. These are not theoretical concerns; rather, all these patterns have already been demonstrated in studies of the effects of lead and air pollution. However, recent regulatory impact assessments for these exposures have generally not incorporated these findings. Therefore, differential risk and vulnerability is a critically important but neglected area within risk assessment, and should be incorporated in the future.

The role of urban municipal governments in reducing health inequities: A meta-narrative mapping analysis

BACKGROUND

The 1986 Ottawa Charter for Health Promotion coincided with a preponderance of research, worldwide, on the social determinants of health and health inequities. Despite the establishment of a 'health inequities knowledge base', the precise roles for municipal governments in reducing health inequities at the local level remain poorly defined. The objective of this study was to monitor thematic trends in this knowledge base over time, and to track scholarly prescriptions for municipal government intervention on local health inequities.

METHODS

Using meta-narrative mapping, four bodies of scholarly literature - 'health promotion', 'Healthy Cities', 'population health' and 'urban health' - that have made substantial contributions to the health inequities knowledge base were analyzed over the 1986-2006 timeframe. Article abstracts were retrieved from the four literature bodies using three electronic databases (PubMed, Sociological Abstracts, Web of Science), and coded for bibliographic characteristics, article themes and determinants of health profiles, and prescriptions for municipal government interventions on health inequities.

RESULTS

1004 journal abstracts pertaining to health inequities were analyzed. The overall quantity of abstracts increased considerably over the 20 year timeframe, and emerged primarily from the 'health promotion' and 'population health' literatures. 'Healthy lifestyles' and 'healthcare' were the most commonly emphasized themes in the abstracts. Only 17% of the abstracts articulated prescriptions for municipal government interventions on local health inequities. Such interventions included public health campaigns, partnering with other governments and non-governmental organizations for health interventions, and delivering effectively on existing responsibilities to improve health outcomes and reduce inequities. Abstracts originating from Europe, and from the 'Healthy Cities' and 'urban health' literatures, were most vocal regarding potential avenues for municipal government involvement on health inequities.

CONCLUSIONS

This study has demonstrated a pervasiveness of 'behavioural' and 'biomedical' perspectives, and a lack of consideration afforded to the roles and responsibilities of municipal governments, among the health inequities scholarly community. Thus, despite considerable research activity over the past two decades, the 'health inequities knowledge base' inadequately reflects the complex aetiology of, and solutions to, population health inequities.