Human health and the environment

Exposure to poor air quality can damage human health and incur associated costs. The severity of these impacts is not uniform around the globe, but depends on the health and density of the populations.

Human physiological thresholds for uncompensable heat stress were exceeded for more than 300 hours in South Asia between 1995 and 2020, including in the evenings, according to an analysis of the diurnal variability of wet and dry bulb temperatures in station data.

Dong et al. analyse Aedes-borne diseases (ABDs) presence, local climate, and socio-demographic factors of 2,469 municipalities in Mexico, and apply machine learning to predict areas most at risk of ABDs clusters. Dengue was most prevalent, and socio-demographic and climatic factors influenced ABDs occurrence in different regions of Mexico.

Exposure to dangerous heat index levels will likely increase by 50-100% in the tropics and by a factor of 3-10 in the mid-latitudes by 2100, even if the Paris Agreement goal of limiting warming to 2°C is met, according to probabilistic projections of global warming.

Tian et al. use mathematical modelling to estimate the impact of various interventions on malaria incidence on Hainan Island, also taking into account climate change. They find that although malaria transmission has been exacerbated by climate change, insecticide-treated bed nets and other interventions were effective in controlling the disease.

Complete savannization of the Amazon Basin would enhance the effects of climate change on local heat exposure and pose a risk to human health, according to climate model projections.

More than 15 million cases of respiratory and cardiovascular infections could be prevented, saving $2 billion USD each year in human health costs by protecting indigenous lands in the Brazilian Amazon, suggest estimates of PM2.5 health impacts between 2010 and 2019.

National safety standard for concentrations of arsenic and cadmium in commercial rice in China are sufficiently high to pose non-negligible health risks especially for chronically exposed children, according to a regionally resolved probability and fuzzy analysis for China.

SDG 6.3 targets to half the proportion of untreated wastewater discharged to the environment by 2030 will substantially improve water quality globally, but a high-resolution surface water quality model suggests key thresholds will still not be met in regions with limited existing wastewater treatment.

Fine particulate aerosols sampled around the Arabian Peninsula predominantly originate from anthropogenic pollution and constitute one of the leading health risk factors in the region, according to shipborne sampling and numerical atmospheric chemistry modelling.

Enhanced rock weathering is competitive with other carbon sequestration strategies in terms of land, energy and water use with its overall sustainability dependent on that of the energy system supplying it, according to a process-based life cycle assessment.

How a nuclear power phase-out may affect air pollution, climate and health in the future is up for debate. Here the authors assess impacts of a nuclear phase-out in the United States on ground-level ozone and fine particulate matter (PM_2.5).

Heat waves and droughts increase air pollution from power plants in California, which disproportionately damages counties with a majority of people of color. Droughts cause chronic increases in pollution damages. Heat waves are responsible for the days with the highest damages.

Inhaled particulates from environmental pollutants accumulate in macrophages in lung-associated lymph nodes over years, compromising immune surveillance via direct effects on immune cell function and lymphoid architecture. These findings reveal the importance of improved air quality to preserve immune health against current and emerging pathogens.

Millions of premature deaths each year can be attributed to ambient particulate air pollution. While exposure to harmful particulates decreases in future scenarios with reduced fossil fuel combustion, across much of the globe, socio-demographic factors dominate health outcomes related to air pollution.

A systematic review shows that >58% of infectious diseases confronted by humanity, via 1,006 unique pathways, have at some point been affected by climatic hazards sensitive to GHGs. These results highlight the mounting challenge for adaption and the urgent need to reduce GHG emissions.

Population growth and dietary changes affect ammonia emissions from agriculture and the concentration of particulate matter in the atmosphere. This study quantifies the adverse health impacts associated with these processes in China using a mechanistic model of particulate matter formation and transport. It also compares them with direct health impacts of changing diets upon premature death from food-related diseases.

Climate mitigation policies often provide health co-benefits. Analysis of individual power plants under future climate–energy policy scenarios shows reducing air pollution-related deaths does not automatically align with emission reduction policies and that policy design needs to consider public health.

Current and future climate change is expected to impact human health, both indirectly and directly, through increasing temperatures. Climate change has already had an impact and is responsible for 37% of warm-season heat-related deaths between 1991 and 2018, with increases in mortality observed globally.

Heat extremes threaten the health of urban residents with particularly strong impacts from day–night sustained heat. Observation and simulation data across eastern China show increasing risks of compound events attributed to anthropogenic emissions and urbanization.