Worldwide trend of atmospheric mercury since 1995

Abstract

Abstract. Concern about the adverse effects of mercury on human health and ecosystems has led to tightening emission controls since the mid 1980s. But the resulting mercury emissions reductions in many parts of the world are believed to be offset or even surpassed by the increasing emissions in rapidly industrializing countries. Consequently, concentrations of atmospheric mercury are expected to remain roughly constant. Here we show that the worldwide atmospheric mercury concentrations have decreased by about 20 to 38 %

Influences on and patterns in total gaseous mercury (TGM) at Harwell, England

“…The data also indicate a 14% decline in average TGM concentration between 1995/6 and 2013, from 1.68 ng m -3 to 1.45 ng m -3 . This places this study broadly in line with observations at other monitoring stations in the northern hemisphere, some of which showed a decline of between 20 and 38% 36,58 .…”

“…Through improvements in industrial processes and emission controls, atmospheric mercury levels have been gradually declining since then 36,37 , and currently the average northern hemispherical background concentration is between 1.4 and 1.7 ng m -3 . 22,36,[38][39][40] Ever since the diagnosis of Minamata disease in 1960 41 , the effects of mercury on the health of both humans 42 and wildlife 43,44 has made the interest in atmospheric mercury more prominent, with the highest risk to human health thought to be through the consumption of fish with elevated levels of mercury, which have bioaccumulated through the food chain into higher predators [45][46][47] . Health policy reflects this risk, with several industrialised countries issuing fish consumption guidelines.…”

Elemental mercury (Hg(0)) in air and surface waters of the Yellow Sea during late spring and late fall 2012: Concentration, spatial-temporal distribution and air/sea flux

“…The analyzer determined the atmospheric Hg by amalgamation onto gold traps with subsequent thermal desorption and the Cold Vapor Atomic Fluorescence Spectrophotometry (CVAFS) detection. Since the particulate matter and reactive gaseous Hg (RGM) in the air stream are removed by a Teflon filter before they reach the gold trap, it is widely accepted that the Tekran Hg analyzer adopted with this procedure determines GEM in the air sample (Slemr et al, 2011;Weiss-Penzias et al, 2013). Air was sampled at 1.5 L min À1 and the GEM was pre-concentrated on the gold traps for 10 min.…”

Trend and seasonal variation of atmospheric mercury concentrations at the Cape Point GAW observatory, South Africa

“…An analysis of the low resolution data (about 150 measurements per year, each covering 3 h sampling time) by Slemr et al (2008) revealed a substantial decreasing trend and a seasonal variation with maximum GEM concentrations in austral summer. Slemr et al (2011) analyzed the combined low and high resolution data until the end of 2009 and found: a) no evidence of a data discontinuity due to the change in techniques, b) an agreement with ship measurements made in the vicinity of Cape Point and c) a pronounced decreasing trend amounting to -0.034 ± 0.005 ng m -3 yr -1 .…”

“…Two techniques were used: a low resolution manual technique until the end of 2004 ) and a high resolution automated technique since March 2007 (Slemr et al, 2011). An analysis of the low resolution data (about 150 measurements per year, each covering 3 h sampling time) by Slemr et al (2008) revealed a substantial decreasing trend and a seasonal variation with maximum GEM concentrations in austral summer.…”