Editorial: The society for environmental geochemistry and health (SEGH): 50 years and beyond.

When the SEGH international board released a short editorial paper back in 2019, we described an aim to increase the membership offering, whilst improving the diversity of input regionally, by scientific discipline and to ensure greater and more regular contact across the regions from 2020 onwards. Wider aspirations described in 2019 (Watts et al. 2019) are discussed within this short communication at the end of 2021 to evaluate progress made. In particular, how the SEGH community adapted to the unprecedented circumstances that have challenged each and every one of us throughout the COVID-19 pandemic since early 2020 and are likely to influence our activities for the foreseeable future.

Lanthanoid analysis in seawater by seaFAST-SP3™ system in off-line mode and magnetic sector high-resolution inductively coupled plasma source mass spectrometer.

Analysis of lanthanoids in seawater is challenging due to the complex matrix (∼35 g L-1 TDS) and low dissolved concentrations (in ng L-1). A 4-step strict analytical protocol and state-of-the-art technology were implemented and validated in this study. The 4-steps method involves the 1) sample filtration and acidification (pH<2); 2) pre-concentration by the matrix separation system, 3) off-line injection of the eluted sample; and 4) determination of lanthanoids by high-resolution inductively coupled plasma mass spectrometer (HR-ICP-MS). Since there are no certified values for lanthanoids in seawater are available, the method validation was done by analyzing SLEW-3 (estuarine water reference samples) and comparing with other reports and artificial seawater (100 ng L-1 lanthanoid multi-element standard solutions). SLEW-3 recovery varied from 78.6% to 106% and in artificial samples it ranged from 87 to 110%. Low recovery can be explained by complex organic in seawater, because the UV oxidation was not performed in the acidified samples. The variation was ≤10%, except for Gd, Tb, and Yb (11-13.75%). Blanks varied between 0.01 and 0.07 ng L-1, except for La and Ce (0.13-0.21 ng L-1). Blanks represent <5% SLEW-3 values and <1% synthetic seawater. The procedural detection limit varied from 0.01 to 0.03 ng L-1.•Lanthanoids as geochemical tracers in seawaters•A 4-step strict analytical protocol and state-of-the-art technology for lanthanoids analyses in seawaters•Sample pre-concentration system for matrix separation for the detection of ultra-low lanthanoids levels.

Geogenic lanthanoid signature in coastal and marine waters from the southern Gulf of California.

Lanthanoids in the southern Gulf of California (GC) seawater are reported for the first time. Lanthanoids showed differences between peninsular and continental coastline, coastal or marine ecosystems, and dry or rainy season. The chondrite-normalized values showed high variability but followed a same pattern. Light lanthanoids were more enriched than heavy ones. Values of ∑Ln and La/Lu were higher in continental than peninsular coastlines, coastal than adjacent marine ecosystems, and rainy than dry season. Differences were related to the lithology and perturbation degree of the ecosystem watersheds. The chondrite-normalized patterns are typical of geological origin. Slightly negative Ce anomaly was related to the low levels of oxygen in water for the oxidation of Ce (III) to Ce (IV) and its posterior scavenging. Negative δEu anomaly is explained by an influx of fluvial and eolian materials from the upper continental, while a positive Eu anomaly related to hydrothermal vent inputs was non-evidenced.

Evaluation of possible impact on human health of atmospheric mercury emanations from the Popocatépetl volcano.

The contribution of Hg from volcanic emanations is decisive for assessing global mercury emissions given the impact of this highly toxic contaminant on human health and ecosystems. Atmospheric Hg emissions from Popocatépetl volcano and their dispersion were evaluated carrying out two gaseous elemental mercury (GEM) surveys during a period of intense volcanic activity. Continuous GEM measurements were taken for 24 h using a portable mercury vapor analyzer (Lumex RA-915M) at the Altzomoni Atmospheric Observatory (AAO), 11 km from the crater. In addition, a long-distance survey to measure GEM was conducted during an automobile transect around the volcano, covering a distance of 129 km. The evaluation of the GEM data registered in the fixed location showed that heightened volcanic activity clearly intensifies the concentration of atmospheric Hg, extreme values around 5 ng m-3. Highest concentrations of GEM recorded during the mobile survey were about 10 ng m-3. In both surveys, the recorded concentrations during most of the measurement time were below 2 ng m-3, but measurements were taken at a considerable distance from the crater, and GEM is subject to dilution processes. During both surveys, recorded GEM did not exceed the 200 ng m-3 concentration recommended by the WHO (Air quality guidelines for Europe, 2000) as the regulatory limits for Hg in the atmospheric environment for long-term inhalation. Because this study was carried out in inhabited areas around the volcano during a period of intense volcanic activity, it can be concluded that the Popocatépetl does not represent a risk to human health in terms of Hg.