Metal Content in Air Samples Collected in an Urban Zone in Tampico, México: A First Survey

ABSTRACT

With the aim to know possible risks to the population, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Tl were determined for the first time in airborne samples of particulate matter in an urban zone in Tampico, México, during the winter of 2003. The 24-hour PM₁₀ samples were collected every 6 days on quartz-filters by using a high volume sampler and analyzed by Inductively Coupled Plasma Optical Emission Spectrometer. Standard reference material was used to verify metal recovery. The maximum PM₁₀ and lead concentrations were 12.05 and 0.040 μ g/m³, respectively, not exceeding Méxican standard values. The greatest metal concentration was that of manganese with 0.90 μ g/m³, followed by Cu and Ni with 0.17 and 0.012 μ g/m³, respectively. Agglomerates, well-defined particles, and heavy metals (e.g., Mn and Cu) were found in PM₁₀ using Scanning Electron Microscopy and Energy Dispersive Spectroscopy. Meteorological conditions associated with the sampling period showed that Pb and Ni are being continuously emitted, and that Mn, Cu, and Co could come from one industry located to the WSW of the region. All of these concentrations do not constitute a potential risk to human health, although it is necessary to continue studying the high concentrations of Mn and Cu in longer sampling periods.

Key Words:

• PM₁₀
• air pollution
• México
• airborne lead
• airborne manganese

ACKNOWLEDGMENTS

This work was supported by the Consejo General de Posgrado e Investigación of the Instituto Politécnico Nacional under the project No. CGPI-20050979. The authors thank the Dirección de Medio Ambiente del Municipio de Tampico, Tamaulipas; the Dirección de Recursos Naturales y Medio Ambiente de la Secretaria de Obras Publicas Desarrollo Urbano y Ecología in Tamaulipas for providing filters and PM₁₀ data; and the Centro de Investigación y Desarrollo Tecnológico of PEÑOLES Inc., for the facilities and course provided. Thanks are also due to Comisión Nacional del Agua and Servicios a la Navegación en el Espacio Aéreo Mexicano for providing meteorological data. VMA is also indebted to SNI for the distinction of her membership and the stipend received.

Notes

¹National Automatic Network for Atmospheric Monitoring.

²Comisión Nacional del Agua.

*These values represent mean concentration of metals.