Air Pollutants in Puerto Rico: Carcinogenic Properties and Mechanisms

Air Pollutants pose a growing public health concern in Puerto Rico (PR), particularly from rapid industrialization, military activities, environmental changes and natural disasters. Criteria and hazardous air pollutants (HAPs) emissions from these sources include 193 chemicals— e.g., particulate matter (PM), carbon monoxide, volatile organic compounds, and heavy metals —coincide with rising respiratory disease rates (e.g. lung cancer) documented in national and regional health registries. This study aimed to review major air pollutants in PR, their molecular carcinogenic mechanisms (mostly focused on respiratory-related cancers), and the geographic areas impacted significantly. We conducted an extensive literature search utilizing peer-reviewed scientific articles (PubMed and Web of Science), governmental reports (EPA, WHO, State of Global Air), public health registries (Puerto Rico Central Cancer Registry and International Agency for Research on Cancer) and local reports. Data on pollutant type, source, molecular pathways, and carcinogenic properties were extracted and synthesized. Our analysis identified ethylene oxide (EtO), polycyclic aromatic hydrocarbons, and particulate matter (PM) from industrial sites as key pollutants. The municipalities of Salinas and Vieques, hubs of industrial activity and military exercises, respectively, emerged as critical hotspots where high concentrations of monitored pollutants (e.g., EtO, formaldehyde, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and diesel PM) are associated with a significant prevalence of cancer and respiratory diseases. These agents, known to induce genomic instability and chromosomal aberrations, were correlated with elevated local cancer incidence. Our findings underscore the urgent need for targeted public health interventions and support a multi-pronged strategy that includes: 1) enhanced regulatory oversight of EtO and other hazardous air pollutant emissions; 2) community-based biomonitoring of high-risk populations; and 3) investment in public health infrastructure and a transition to cleaner energy sources. Integrating rigorous environmental science with public health advocacy is essential to strengthen PR’s cancer-control continuum and foster resilience in its most vulnerable communities.