Chemical Composition, Fluxes and Seasonal Variation of Acid Deposition in Carmen Island, Campeche, Mexico

R. M. Cerón, J. G. Cerón, C. G. Carballo, C. A. Aguilar, C. Montalvo, J. A. Benítez, Y. J. Villareal, M. M. Gómez

EPOMEX Institute, Autonomous University of Campeche, San Francisco de Campeche, Mexico.
Research Center on Environmental Sciences, Autonomous University of Carmen, Carmen City, Mexico.

DOI: 10.4236/jep.2013.48A1007                

Abstract

Two hundred and seven rain events from April to October 2012 were collected in Carmen Island, Campeche, Mexico, and the concentration of 8 major ions with the pH of the rainwater was analyzed. Chemical composition variations as a result of seasonal patterns, meteorological conditions, and mixed local and regional sources contribution were assessed. In spite of the fact that nitrate and sulfate levels were higher than background hemispheric values, the average pH values were almost neutral. Carmen Island was under the influence of both, local and long-range transported emissions. Chemical composition showed a dilution effect as a result of the monthly rainfall amount. Ca²⁺ and Na⁺ were the most abundant ions, and these ions acted as acid neutralizers and buffered the acidity of the rain, suggesting that marine and crustal aerosols played an important role in the acid-base interactions. Wet deposition fluxes obtained were compared with reference values proposed as critical loads, fluxes obtained in this study did not exceed the critical values reported for sensitive ecosystems in Europe, indicating that this site has yet enough capacity to support acidity, nitrogen and sulfur deposition. However, it is necessary to obtain reference values characteristics for tropical regions.

Keywords

Trace Elements; Acid Deposition; Deposition Fluxes; Critical Loads; Acid Rain; Campeche; Mexico

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	P. Brimblecombe, “Acid Rain 2000 + 1000,” Water, Air, & Soil Pollution, Vol. 130, No. 1-4, 2001, pp. 25-30. doi:10.1023/A:1012235015654
[2]	R. Cerón, J. Cerón and M. Muriel, “Influence of Geochemical and Anthropogenic Sources on Rainwater Chemical Composition in Two Coastal Sites Impacted by the Gas and Oil Industry in Campeche, Mexico,” WIT Transactions on Ecology and the Environment, Vol. 88, 2006, pp. 419-428.
[3]	NMX-AA-079-SCFI-2001, “Water Analysis. Determination of Nitrates in Natural Waters, Drinking Water, Effluents and Treated Wastewaters,” 2001.
[4]	NMX-AA-073-SCFI-2001, “Water Analysis. Determination of Chlorides in Natural Waters, Drinking Water, Effluents and Treated Wastewaters,” 2001.
[5]	NMX-AA-074-1981, “Water Analysis. Determination of Sulfate Ion in Natural Waters, Drinking Water, Effluents and Treated Wastewaters,” 1981.
[6]	US EPA, “Method 7770: Methods for Chemical Analysis of Water and Wastes,” US Environmental Protection Agency, Office of Research and Development, Washington DC, 1986.
[7]	US EPA, “Method 7610: Methods for Chemical Analysis of Water and Wastes,” US Environmental Protection Agency, Office of Research and Development, Washington DC, 1986.
[8]	US EPA, “Method 7140: Methods for Chemical Analysis of Water and Wastes,” US Environmental Protection Agency, Office of Research and Development, Washington DC, 1986.
[9]	US EPA, “Method 7450: Methods for Chemical Analysis of Water and Wastes,” US Environmental Protection Agency, Office of Research and Development, Washington DC, 1986.
[10]	J. N. Galloway, J. D. Thornton, S. A. Norton, H. L. Volchok and R. A. N. McLean, “Trace Metals in Atmospheric Deposition: A Review and Assessment,” Atmospheric Environment, Vol. 16, No. 7, 1982, pp. 1677-1700. doi:10.1016/0004-6981(82)90262-1
[11]	H. G. Padilla, R. Belmont, M. B. Torres and A. P. Báez, “Hurricanes Pauline and Nora rainwater chemical composition,” Canadian Journal of Earth Sciences, Vol. 37, No. 4, 2000, pp. 569-578. doi:10.1139/e99-114
[12]	D. Y. Huang, Y. G. Xu, P. Peng, H. H. Zhang and J. B. Lan, “Chemical Composition and Seasonal Variation of Acid Deposition in Guangzhou, South China: Comparison with Precipitation in Other Major Chinese Cities,” Environmental Pollution, No. 157, No. 1, 2009, pp. 35-41. doi:10.1016/j.envpol.2008.08.001
[13]	K. Huang, G. S. Zhuang, C. Xu, Y. Wang and A. H. Tang, “The Chemistry of the Severe Acidic Precipitation in Shanghai, China,” Atmospheric Research, Vol. 89, No. 1-2, 2008, pp. 149-160. doi:10.1016/j.atmosres.2008.01.006
[14]	P. Grennfelt and J. Nilsson, “Critical Loads for Sulphur and Nitrogen,” Workshop Report on Critical Loads for Sulphur and Nitrogen, Skokloster, 19-24 March 1988, pp. 415-418.