Survey of atmospheric total gaseous mercury in Mexico

While sources of gaseous mercury (natural and anthropogenic) are well known, studies on atmospheric mercury concentrations in Mexico are new. In order to assess the total gaseous mercury (TGM) levels at some characteristic Mexican sites, four locations were selected to start an exploratory survey and begin to asses the TGM behavior. This paper presents data obtained at an urban site (Mexico City), a rural site (Huejutla, Hidalgo), a coastline site (Puerto Angel, Oaxaca) and a closed mining site (Zacatecas City, Zacatecas). The highest TGM average values were found at this last site (71.82 ng m−3) together with the urban site (9.81 ng m−3). At the rural and coast line sites the lowest TGM values (1.32 and 1.46 ng m−3, respectively) were found. According to the ANOVA test, there were significant differences for the TGM values among all the studied sites, except between the coastline and the rural place. A multiple correlation test performed between TGM and some meteorological parameters showed that in sites without anthropogenic mercury sources influence (rural and coast line), the TGM levels are correlated with the temperature and relative humidity, while for the other two sites no clear correlation was found.