Climate change is one of the biggest challenges for humankind. It is linked to many different types of environment distress, such as extreme temperatures, spread of tropical diseases and their vectors, and air pollution. Air pollution is already the most significant environmental health risk and a major cause of death and disability, causing approximately 7 million premature deaths annually, and its future impact is likely to be even greater if adequate policy action is not developed. Moreover, 99% of the global population breathe air exceeding WHO air-quality guidelines, with low- and middle‑income countries suffering from the highest exposures (WHO, 2026[1]).
While the economic cost of heat-related mortality varies widely across the LAC region, the overall burden has consistently increased over the last decades. In LAC27, the average annual monetised global losses due to heat related mortality for 2020-2024 were 244% higher than the 2000-2004 average, expressed as the equivalent number of average annual incomes (Figure 4.25). In 2024, this burden was the lowest in Bahamas, Saint Vincent and the Grenadines and Belize, where losses remain below 1000 average annual income equivalents. For instance, in Saint Vincent and the Grenadines the loss is equivalent to about 322 annual incomes. At the opposite end, Mexico and Brazil showed very high losses, reaching 409 384.8‑ and 498 325.9‑income equivalents, respectively.
Dengue is a mosquito-borne viral disease transmitted by the Aedes aegypti and Aedes albopictus species. The basic reproduction number (R0) for dengue has increased across LAC when comparing 2015‑2024 with 1951‑1960. On average, LAC25 had an increase of 0.23 for Ae. aegypti and of 0.25 for Ae. albopictus species, meaning that each case now leads, on average, roughly a quarter more secondary infections than in the 1951‑1960 period (Figure 4.26). Colombia, Ecuador and Nicaragua exhibited the largest increases in aegypti-related R0 (over 0.7), while Brazil, Bolivia and Colombia, showed the highest gains for albopictus-related R0 (above 0.59). Only a few countries experienced declines in the dengue R0, with Trinidad and Tobago, Haiti, Dominican Republic, Jamaica and Argentina experiencing reductions for Ae. aegypti (ranging from ‑0.20 to ‑0.04) and Cuba, Uruguay and Argentina for Ae. albopictus (from ‑0.30 to ‑0.03).
In LAC31 countries, mortality rates attributed to household and ambient air pollution in 2019 were on average 42.1 age‑standardised deaths per 100 000 population for females and 53.7 for males. Mortality rates for men were higher than for women across all LAC countries with available data, except in Haiti. Haiti had the highest mortality rates for both women and men at 216 and 204 deaths per 100 000 population, respectively. Bahamas, Panama, Antigua and Barbuda, and Barbados had the lowest male mortality rates in the region, with less than 22 deaths per 100 000 population, while the lowest female mortality rates were in Bahamas and Uruguay with less than 12 deaths per 100 000 population (Figure 4.27).
Climate change is altering the ecology of dengue vector mosquitoes and expanding the geographic areas where species can live. While Ae. aegypti is adapted to warmer urban environments (24‑34°), Ae. albopictus is more prevalent in cooler suburban and rural environments (15‑30°), however, it is now expanding into temperate regions that were previously only populated by Ae. Aegypti, increasing projected dengue infection risk (Chacón and Santos-Vega, 2026[2]). PAHO recommends sustained dengue surveillance, targeted mosquito-control in high-risk areas, and strong clinical care to prevent severe cases and deaths. Communities play a key role in prevention actions supported by health education campaigns. Finally, improving diagnostics, increasing early detection and advancing research on vaccines is essential to strengthen dengue prevention (Anand et al., 2024[3]).
