Charting achievements: a two-year retrospective of the society for environmental geochemistry and health (SEGH) and the evolving strategies.

Emerging from the shadow of the COVID-19 pandemic, it is time to ground ourselves and retrospectively assess the recent achievements of SEGH over the past years. This editorial serves as a comprehensive report on the progress made in comparison to the aspirations and goals set by the society's board in 2019 (Watts et al., Environ Geochem Health 42:343-347, 2019) (Fig. 1) and reflects on the state of the SEGH community as it reached its 50th anniversary at the close of 2021 (Watts et al. Environ Geochem Health 45:1165-1171, 2023). The focus lies on how the SEGH community navigated through the extraordinary challenges posed by the COVID-19 pandemic since early 2020, and to what extent the 2023 targets have been met.

The mechanisms of detoxification of As(III), dimethylarsinic acid (DMA) and As(V) in the microalga Chlorella vulgaris.

The response of Chlorella vulgaris when challenged by As(III), As(V) and dimethylarsinic acid (DMA) was assessed through experiments on adsorption, efflux and speciation of arsenic (reduction, oxidation, methylation and chelation with glutathione/phytochelatin [GSH/PC]). Our study indicates that at high concentrations of phosphate (1.62mM of HPO4(2-)), upon exposure to As(V), cells are able to shift towards methylation of As(V) rather than PC formation. Treatment with As(V) caused a moderate decrease in intracellular pH and a strong increase in the concentration of free thiols (GSH). Passive surface adsorption was found to be negligible for living cells exposed to DMA and As(V). However, adsorption of As(III) was observed to be an active process in C. vulgaris, because it did not show saturation at any of the exposure periods. Chelation of As(III) with GS/PC and to a lesser extent hGS/hPC is a major detoxification mechanism employed by C. vulgaris cells when exposed to As(III). The increase of bound As-GS/PC complexes was found to be strongly related to an increase in concentration of As(III) in media. C. vulgaris cells did not produce any As-GS/PC complex when exposed to As(V). This may indicate that a reduction step is needed for As(V) complexation with GSH/PC. C. vulgaris cells formed DMAS(V)-GS upon exposure to DMA independent of the exposure period. As(III) triggers the formation of arsenic complexes with PC and homophytochelatins (hPC) and their compartmentalisation to vacuoles. A conceptual model was devised to explain the mechanisms involving ABCC1/2 transport. The potential of C. vulgaris to bio-remediate arsenic from water appeared to be highly selective and effective without the potential hazard of reducing As(V) to As(III), which is more toxic to humans.

Effects of temperature on metal tolerance and the accumulation of Zn and Pb by metal-tolerant fungi isolated from urban runoff treatment wetlands.

AIMS: To investigate the ability of two fungi to accumulate Zn and Pb, the effect of temperature on their metal tolerance and possible mechanisms involved in metal accumulation. METHODS AND RESULTS: Beauveria bassiana and Rhodotorula mucilaginosa isolated from constructed wetlands receiving urban runoff were grown in modified glycerol asparagine medium containing elevated levels of Zn and Pb at 30 degrees C. Beauveria bassiana accumulated up to 0.64% of available Zn and 8.44% of Pb. The corresponding values for R. mucilaginosa were up to 2.05% for Zn and 16.55% for Pb. Radial growth of colonies grown at 4 degrees and 30 degrees C on agar containing Zn or Pb indicated that metal tolerance was not seriously affected by a decrease in temperature. Transmission electron microscopy and emission dispersion x-ray spectrophotometry suggested that the mechanism of resistance in B. bassiana may be associated with the precipitation of Pb (possibly in the form of oxalates). CONCLUSION: The processes of biosorption could potentially occur throughout the year with both living and dead cells able to accumulate metals. SIGNIFICANCE AND IMPACT OF THE STUDY: Identified precipitation processes could be an important mechanism in metal removal in wetland substrates serving as long-term storage sinks.

Point Defiance: a case study of the United States' first public needle exchange in Tacoma, Washington.

The first publicly funded needle exchange program in the United States began in Tacoma, Washington, in August 1988. The exchange's history is characterized by a series of firsts: the first American publicly funded exchange; the first pharmacy exchange; the first American needle delivery program; and the first state Supreme Court ruling not only supporting the existence of a needle exchange program but superseding existing drug paraphernalia laws. It is also unique because it began outside of the public health system and was not compromised by political feasibility. This article documents the events and personalities which led to the exchange's establishment and its expansion over time; the program's local, state and legal challenges and advocates; its portrayal in the local and national media; the research that documented its successes; and its important contribution to the fight for drug users' unencumbered access to sterile needles.

Survival and nodulating ability of indigenous and inoculated Rhizobium leguminosarum biovar trifolii in sterilized and unsterilized soil treated with sewage sludge.

Rhizobium leguminosarum biovar trifolii was detected in soil from 41 of 47 plots, within nine sewage sludge-treated sites with different soil characteristics and heavy metal contents. However, although population size varied widely, there was no consistent correlation with soil heavy metal concentration. Indigenous populations in 20 plots within four selected sites retained their ability to induce effective nodule formation after incubation of soil in the dark for 165 days. In sterilized (gamma-irradiated) soil, Rhizobium survival varied from 0.01% to 95% depending on the soil sample and strain used. Metal-resistant strains with non-mucoid colonies survived less well than mucoid metal-sensitive strains.

Syringe exchange in the United States, 1996: a national profile.

OBJECTIVES: This paper provides 1996 information on the status of US syringe exchange programs and compares these findings with data from our 1994 survey. METHODS: In November 1996, questionnaires were mailed to 101 syringe exchange programs. Program directors were contacted to conduct telephone interviews based on the mailed questionnaires. Data collected included number of syringes exchanged, syringe exchange program operations, legal status, and services offered. RESULTS: Eighty-seven programs participated in the survey. A total of 46 (53%) were legal, 20 (23%) were illegal but tolerated, and 21 (24%) were illegal-underground. Since 1994, there has been a 54% increase in the number of cities and a 38% increase in the number of states with syringe exchange programs. Eighty-four programs reported exchanging approximately 14 million syringes, a 75% increase from 1994. Syringe exchange programs also provided a variety of other services and supplies, and legal programs were more likely than illegal ones to provide these services. CONCLUSION: Despite continued lack of federal funding, syringe exchange programs expanded in terms of the number of syringes exchanged, the geographic distribution of programs, and the range of services offered.

Reduced risk of hepatitis B and hepatitis C among injection drug users in the Tacoma syringe exchange program.

OBJECTIVES: This case-control study examined the association between syringe exchange use and hepatitis B and C in injection drug users. METHODS: Case patients included 28 injection drug users with acute hepatitis B and 20 with acute hepatitis C reported to the health department in a sentinel hepatitis surveillance county; control subjects were injection drug users with no markers of exposure to hepatitis B or C (n = 38 and 26, respectively) attending health department services during the same period. Data were abstracted from clinic records. RESULTS: Seventy-five percent of case patients with hepatitis B and 26% of control subjects had never used the exchange; similar proportions were found for the hepatitis C case and control groups. After adjustment for demographic characteristics and duration of injecting drugs, nonuse of the exchange was associated with a sixfold greater risk of hepatitis B (odds ratio [OR] = 5.5; 95% confidence interval [CI] = 1.5, 20.4) and a sevenfold greater risk of hepatitis C (OR = 7.3; 95% CI = 1.6, 32.8). CONCLUSIONS: The results suggest that use of the exchange led to a significant reduction in hepatitis B and hepatitis C in the county and may have also prevented a substantial proportion of human immunodeficiency virus infections in injection drug users.

An interview study of participants in the Tacoma, Washington, syringe exchange.

Although European and Australian studies of syringe exchange programs have reported safer injection among participants and no increase in drug use, the generalizability of these findings to the US is uncertain. We report on the operations and potential effectiveness of the longest-operating syringe exchange in the US and compare our results to studies of exchange programs outside the US. The sample of 204 study subjects reported no change in the frequency of injection, from 155 to 152 injections per month, and a decline in the frequency of unsafe injections, from 56 to 30 times per month, while participating in the program. In all studies, participants report reduction in unsafe injections, and no increase in illicit drug use. However, the comparison also suggests that a high proportion of Tacoma exchangers have higher initial rates of drug injection, unsafe injection and homelessness, all of which were associated with unsafe injection while using the exchange. These indicate a need for additional services but that the Tacoma program is no less effective than European and Australian programs.

The Tacoma Syringe Exchange.

For over a year, the Tacoma Syringe Exchange has been operating in spite of existing drug paraphernalia laws. One hundred fifty-four subjects have been interviewed regarding drug injection practices for the month prior to first use of the exchange and for the most recent month since using the exchange. Statistically significant reductions in mean frequency of obtaining used syringes, and in mean rate of passing on used syringes, have been reported. Mean number of times bleach was used to disinfect contaminated syringes has risen. The exchange continues to attract mainly men, median age 35, with a long history of injection. No differences have been observed in mean number of injections per month. In order to increase utilization, new sites are planned, but expansion has been hampered by a series of legal problems. Since the exchange draws many difficult to reach individuals, it is an important location for STD screening and drug treatment recruitment. Documentation of participation patterns and barriers to exchange use, and effects upon HIV serological status are recommended.