Temporal variation of the PM_2.5/PM₁₀ ratio and its association with meteorological factors in a South American megacity: Metropolitan Area of Lima-Callao, Peru

José Abel Espinoza-Guillen ¹, Marleni Beatriz Alderete-Malpartida ², Ursula Fiorela Navarro-Abarca ²

⁰Programa de Maestría en Ciencias Ambientales, Universidad Nacional Agraria La Molina, Av. La Molina S/N, Lima, Perú. 20190609@lamolina.edu.pe.

Environmental Monitoring and Assessment +

|

April 13, 2024

View abstract on PubMed

Summary

Air quality in Lima-Callao shows increasing trends in the fine particulate matter to coarse particulate matter (PM2.5/PM10) ratio, particularly in central areas. This ratio is influenced by meteorological factors like temperature, humidity, and wind speed.

Area Of Science

Environmental Science
Atmospheric Chemistry
Urban Climatology

Background

The Metropolitan Area of Lima-Callao (MALC) faces significant air quality issues due to high concentrations of particulate matter (PM2.5 and PM10).
Limited research exists on the temporal dynamics of the PM2.5/PM10 ratio and its relationship with meteorological variables in MALC.

Purpose Of The Study

To analyze the temporal trends and variability of the PM2.5/PM10 ratio over five years (2015-2019) in MALC.
To investigate the association between the PM2.5/PM10 ratio and key meteorological parameters.

Main Methods

Utilized Theil-Sen estimator for trend analysis.
Employed bivariate polar plots and correlation analysis to assess spatial and temporal relationships.
Analyzed hourly, monthly, and annual data from 2015 to 2019.

Main Results

Highest PM2.5 concentrations were in eastern Lima (ATE station), while highest PM10 were in southern Lima (VMT station).
The PM2.5/PM10 ratio was highest in central Lima (CDM station, 0.55), indicating vehicle emissions, and lowest in southern Lima (VMT station, 0.27), suggesting coarse particle resuspension.
Significant positive trends in the PM2.5/PM10 ratio were observed across northern, central, and southern Lima. The ratio showed negative correlations with wind speed and temperature, and a positive correlation with relative humidity.

Conclusions

The study reveals distinct spatial patterns and increasing temporal trends in the PM2.5/PM10 ratio across MALC.
Meteorological conditions significantly influence the PM2.5/PM10 ratio, impacting pollutant dispersion.
Findings are crucial for developing targeted air pollution control strategies addressing specific emission sources and meteorological influences in Lima.

Keywords:

Air quality Metropolitan Area of Lima-Callao PM2.5/PM10 ratio Particulate matter Temporal variation