Comprehensive review of health impacts of the exposure to nitrogen oxides (NOx), carbon dioxide (CO₂), and particulate matter (PM)

Air pollution is a crucial public health issue, with many pollutants causing various health problems. Consequently, this review aims to provide an integrated assessment of the sources, exposure routes and health effects of three main air contaminants: Carbon Dioxide (CO₂), Nitrogen Oxides (NO_x) and Particulate Matter (PM). While the individual effects of CO₂, NOx, and PM on human health have been widely studied, this review uniquely integrates these findings to offer a holistic overview of their combined impact. It examines the major producers of these pollutants like vehicle exhausts, industrial processes and natural phenomena as well as describing how these agents behave within the environment leading to changes in air quality. The paper also explores the exposure mechanisms and quantifies the associated health risks, highlighting acute and chronic conditions linked to respiratory, cardiovascular, and neurological systems. By synthesizing current research on CO₂, NO_x, and PM, this review underscores the importance of considering the effects of multiple pollutants in public health, thereby contributing to a more integrated approach to air quality management and health risk mitigation. This review addresses the critical gap in understanding the combined health impacts of NOx, CO₂, and PM exposure, a growing concern amid worsening air quality. By integrating diverse research findings, this study highlights the urgent need to reassess environmental health policies, particularly due to the increasing burden on respiratory and cardiovascular systems. Unlike existing literature, this review uniquely synthesizes the synergistic effects of multiple pollutants, thereby informing more comprehensive mitigation strategies to protect human health.