Highlights

• Long-term UFPs exposure significantly increased total non-accidental mortality.

• Mortalities for cardiovascular diseases were associated with UFP exposure.

• Hispanics and non-Hispanic Blacks experienced higher UFP-related mortalities.

• Young children, older adults, and non-NYC residents had higher UFP-Mortality risks.

• Exposure to UFPs during winter season further elevated the mortality risk.

Environmental Implication

Ultrafine particles (UFPs) are airborne particles less than 100 nm in aerodynamic diameter. The small size allows them to enter the body through lung easily and reach the most distal regions within hours. Compared to larger particles, the large surface area to volume ratio enables UFPs to absorb greater amounts of hazardous metal and organic compounds per unit. Our findings address the severest impact of UFPs on human mortality and the critical need for monitoring and regulating UFP levels in