After Hurricane Maria devastated Puerto Rico, indoor air pollution (IAP) became a public health concern. We hypothesize that chronic exposure to IAP affected the immune system of the Puerto Rican population, such as becoming more reactive to pro-inflammatory components present in IAP. To test this, we will compare the human blood leukocytes reactivity of Puerto Ricans exposed to the post-Hurricane Maria IAP and Puerto Ricans not exposed to IAP.