Revealing the air pollution burden associated with internal Migration in Peru

Abstract

This study aims to quantify changes in outdoor (ambient) air pollution exposure from different migration patterns within Peru and quantify its effect on premature mortality. Data on ambient fine particulate matter (PM 2.5) was obtained from the National Aeronautics and Space Administration (NASA). Census data was used to calculate rates of within-country migration at the district level. We calculated differences in PM 2.5 exposure between "current" (2016-2017) and "origin" (2012) districts for each migration patterns. Using an exposure-response relationship for PM 2.5 extracted from a metaanalysis, and mortality rates from the Peruvian Ministry of Health, we quantified premature mortality attributable to each migration pattern. Changes in outdoor PM 2.5 exposure were observed between 2012 and 2016 with highest levels of PM 2.5 in the Department of Lima. A strong spatial autocorrelation of outdoor PM 2.5 values (Moran's I = 0.847, p-value=0.001) was observed. In Greater Lima, ruralto-urban and urban-to-urban migrants experienced 10-fold increases in outdoor PM 2.5 exposure in comparison with non-migrants. Changes in outdoor PM 2.5 exposure due to migration drove 137.1 (95%CI: 93.2, 179.4) premature deaths related to air pollution, with rural-urban producing the highest risk of mortality from exposure to higher levels of ambient air pollution. Our results demonstrate that the rural-urban and urban-urban migrant groups have higher rates of air pollution-related deaths. Migration is increasingly recognized as an important determinant for population health 1-4. Nowadays, more than 244 million international migrants are estimated globally 5 with considerable gaps in health care services. Furthermore, a significantly larger number of internal migrants − people moving within their country of birth − has been documented 4 , with a particular health burden despite being nationals. Migrants are commonly exposed to a range of challenges such as low quality of labor conditions, massive vehicular traffic, sedentarism (low level of physical activity), lack of social support, limited access to healthy food choices 6 , and stress 7,8. Social vulnerability from economic instability, social isolation, poor access to healthcare services, increased exposure to infectious diseases, and traumatic events related to the migration itself have also been known to affect migrants' health 9-14. In addition to these stressors, migrants are exposed to new environments, which may have further impacts. Environmental changes and exposures have been studied as drivers of migration 15-17 , including how exposure to hazards or availability of ecosystem services can lead residents' to migrate away from these harmful environments. Although there is abundant literature studying how environmental hazards can drive emigration, only one study conducted in the United States (U.S.) has investigated how migrants may also be at a differential risk for environmental exposures. Interestingly, this study found that international immigrants in the U.S. are general...

Maternal internal migration and child growth and nutritional health in Peru: an analysis of the demographic and health surveys from 1991 to 2017

“…It has recently been suggested that pollution may play a role in stunting [53] and previous research in Peru found that migrants in Greater Lima had a 10-fold increase in exposure to larger particulate matter (PM2.5) compared to non-migrants [54]. We did not find higher levels of stunting in children of migrants compared to nonmigrants in larger cities but further investigation should compare child growth in areas with different levels of pollution within cities and at different ages.…”

Effect of border policy on exposure and vulnerability to climate change

“…In contrast, established migration networks may increase an individual's propensity to move. Second, either through lack of information about risks at destinations or as the outcome of a balancing of risks, migrants might move to areas that are more or less exposed to climate change impacts than those where they came from (8,9). Third, climate change is likely to lead to resource depletion in some of the most deprived areas, thereby trapping individuals who cannot afford to move (10,11).…”