Indication of change in global and regional trends of atmospheric Mercury concentrations

Abstract

In 1992 we reported an indication of global increase of atmospheric mercury concentrations obtained from the measurements of total gaseous mercury (TGM) over the Atlantic Ocean during five ship cruises between 1977 and 1990 [Slemr and Langer, 1992]. The observed rate of concentration increase and its implications were consistent with previous measurements and the trends derived from analyses of dated peat bog and lake sediment records. To avoid uncertainties from the intermittent character of ship measurements and to obtain more detailed information about this trend, we have continuously monitored TGM concentrations at the summit of the Wank mountain (1780 m a.s.l.) near Garmisch‐Partenkirchen in southern Germany since March 1990. These measurements and the results of another cruise in 1994 indicate a significant change in the trend of global TGM concentration, with a decrease of about 22% in the years between 1990 and 1994. This decrease is most likely the result of reduction in coal consumption and control measures taken in the OECD countries.

A review of worldwide atmospheric mercury measurements

“…All cruises show a pronounced concentration gradient between hemispheres. In addition, a rather homogeneous distribution of TGM in the Southern Hemisphere (SH) was observed during the previous cruises (Slemr et al, 1981(Slemr et al, , 1985(Slemr et al, , 1995Slemr and Langer, 1992). When latitude is taken into account, the TGM concentrations measured on board ship are also comparable to measurements at remote coastal sites such as Mace Head (Ireland), Cape Point (South Africa) and Lista (Norway) (Ebinghaus et al, 2002;Baker et al, 2002).…”

“…Table 2 shows a statistical summary of TGM measurements performed over the northern and southern Atlantic Ocean throughout several cruise campaigns by several research groups from 1977 to 2001 (Slemr and Langer, 1992;Lamborg et al, 1999;Mason et al, 2001;Temme et al, 2003;Laurier and Mason, 2007). The first measurements made on board of ships during north-south cruises over the Atlantic Ocean were made between 1977-1980(Slemr et al, 1981, 1985 and repeated in 1990 and 1994 (Slemr and Langer, 1992;Slemr et al, 1995). In 1996, Lamborg et al (1999) performed Hg measurements in the south and equatorial Atlantic Ocean from Montevideo, Uruguay to Barbados.…”

Polar firn air reveals large-scale impact of anthropogenic mercury emissions during the 1970s

“…Before 1980, the only atmospheric GEM data were obtained during short ship cruises (i.e., a few weeks) across the Atlantic Ocean. These measurements exhibit strong latitudinal gradients with peak values around 40°N and mean values of Ϸ2 ng m Ϫ3 in the northern hemisphere (7,(43)(44)(45). While atmospheric GEM concentrations reconstructed from Summit firn air are higher than mean hemispheric values, they reproduce GEM levels observed shipboard between 40°and 50°N (see Fig.…”

Possible Sources for Some Trace Elements Found in Airborne Particles and Precipitation in Dorset, Ontario

“…These activities alter the natural balance that previously existed in the earth's ecological system. Such activities are numerous, and the more significant ones include the clearing of land and elimination of forests, 1 the mining and smelting of a variety of minerals, 2 and the burning of fossil fuels to generate energy. 3 The importance of studying possible emission sources of trace elements found in the atmosphere is twofold.…”

“…First, many of the trace elements are considered atmospheric pollutants because of their toxicity to humans and other living organisms. Second, these trace elements are often co-emitted with other volatile pollutants, such as hydrocarbons, SO 2 , and NO X that contribute to photochemical smog, organic and inorganic acidic species, and high concentrations of suspended particles that cause visibility degradation. Since most trace elements are nonvolatile and less prone to chemical transformations, they tend to undergo long-range atmospheric transport and remain as part of the primary emitted materials.…”