In situ measurements of speciated atmospheric mercury and the identification of source regions in the Mexico City Metropolitan Area

Abstract

Abstract. In order to expand the currently limited understanding of atmospheric mercury source-receptor relationships in the Mexico City Metropolitan Area, real time measurements of atmospheric mercury were made at a downtown urban site, and a rural site on the outskirts of Mexico City, during March, 2006. Numerous short-lived increases in particulate mercury (PHg) and reactive gaseous mercury (RGM) concentrations were observed at the urban site during the 17 day study, and less frequent increases in gaseous elemental mercury (GEM) concentrations were measured at both the urban and rural sites. The episodic increases observed were attributed to plume impacts from industrial point source emissions in and around Mexico City. Average concentrations and standard deviations measured during the study were as follows: i) Urban site: PHg=187±300 pg m−3, RGM=62±64 pg m−3, GEM=7.2±4.8 ng m−3. ii) Rural site: GEM=5.0±2.8 ng m−3. Several source regions of atmospheric mercury to the urban and rural sites were determined using Concentration Field Analysis, in which atmospheric mercury measurements were combined with back trajectory data to determine source regions. Only some source regions correlated to mercury emission sources listed in the Federal Pollutant Release and Transfer Register, leaving the rest unaccounted for. Contributions of anthropogenic mercury point sources in and around Mexico City to concentration averages measured at the urban site during the study were estimated to be: 93±3% of reactive mercury (PHg and RGM), and; 81±0.4% of GEM. Point source contributions to GEM measured at the rural site were 72±1%. GEM and reactive mercury (PHg and RGM) were not found to correlate with biomass burning at either of the measurement sites.

Atmospheric gaseous elemental mercury (GEM) concentrations and mercury depositions at a high-altitude mountain peak in south China

“…Numerous studies with regard to atmospheric Hg have been carried out at many sites in North America and Europe (e.g., Poissant et al, 2005;Valente et al, 2007;Sigler et al, 2009;Rutter et al, 2009). However, to the best of our knowledge, only a few long-term monitoring studies of atmospheric Hg and deposition fluxes have been performed in semi-rural and urban/industrial areas of China.…”

Potentially-toxic and essential elements profile of AH1N1 patients in Mexico City

“…As shown in Table 4, statistical analysis between blood mercury levels of pneumonia –infected AH1N1 patients versus Controls II (ILI cases) met highly statistical significance while between Controls I (pneumonia cases) and controls II did not. Probable reasons for Hg blood levels found among population living in Mexico City during pandemic influenza might be the content of mercury in airborne particulate matter recently reported in literature11. Mercury belongs to one of the most harmful xenobiotic with severe implications (e.g., kidney impairment) although chronic low-dose exposure remains still not well understood9.…”

Global evaluation and calibration of a passive air sampler for gaseous mercury

“…The atmospheric 90 lifetime of GOM due to reduction and deposition is on the order of days to weeks (Ariya et al, 2015;Horowitz et al, 2017;Shah et al, 2016). Although uncertainties remain, the shorter atmospheric lifetime and higher deposition fluxes of GOM translate to GEM making up the majority of TGM in most places (typically >95%) (Cole et al, 2014;Driscoll et al, 2013;Rutter et al, 2009;Slemr et al, 2015). As such any uncertainty related to the uptake of GOM by the PASs is 95 likely small.…”

“…Information on the percentage data coverage across the deployment periods of the active 150 measurement systems and PASs (successful samples/deployments out of actual samples/deployments) is shown in Table S2 Given that TGM is generally dominated by GEM at most sites (typically >95%) (Cole et al, 2014;Driscoll et al, 2013;Rutter et al, 2009;Slemr et al, 2015), differences between the two concentrations are likely to be small. To ensure consistency with the nomenclature used for the PASs, the analyte sampled by non-speciating Tekran 2537 instruments is referred to as gaseous 160…”