Lithium in drinking water, altitude, and suicide rates in rural areas of Argentinean Andes

The concentration of Lithium in water resources: A systematic review, meta-analysis and health risk assessment

The presence of trace elements such as lithium (Li) in water resources in the long term can endanger consumers' health. Several studies have been conducted on Li concentration in water sources; hence, this study attempted to retrieve studies using a systematic search. The search was conducted in Web of Sciences, Embase, PubMed, and Scopus databases from 1 January 2010 to 15 January 2023. Li concentration was meta-analyzed based on the type of water resources and countries subgroups in the random effects model (REM) statistical analysis. In addition, health risk assessment in different age groups was calculated using the target hazard quotient (THQ). This study included 76 papers with 157 data reports in our meta-analysis. The overall pooled concentration of Li was 5.374 (95 % CI: 5.261-5.487 μg/L). The pooled concentration of Li in groundwater (40.407 μg/L) was 14.53 times surface water (2.785 μg/L). The highest water Li content was attributed to Mexico (2,209.05 μg/L), Bolivia (1,444.05 μg/L), Iraq (1,350 μg/L), and Argentina (516.39 μg/L). At the same time, the lowest water Li content was associated with Morocco (1.20 μg/L), Spain (0.46 μg/L), and India (0.13 μg/L). THQ due to Li in water resources in consumers of Iraq, Mexico, South Africa, Afghanistan, Bolivia, Portugal, Malawi, South Korea, Nepal, South Korea, Argentina, and the USA was higher than 1 value. Therefore, continuous monitoring of Li concentration in water sources and reducing Li concentration, especially in groundwater water, using new water treatment processes in these countries are recommended.

An investigation into the association between suicide mortality rate and lithium levels in potable water: a review study

This study aimed to investigate the association between lithium levels in potable water and suicide mortality rates in the total inhabitants. We systematically searched Embase, PubMed/MEDLINE, Scopus, PubMed Central (PMC), Google Scholar databases, as well as medRxiv using the following keywords: drinking water, lithium, standardized mortality ratio (SMR), tap water, suicide, and ground water. Pearson regression analysis was used to test an association between variables with 95% confidence interval (CI). A value of P < 0.05 was considered significant. A total of 16 eligible articles were identified. Lithium concentrations in drinking water range from 0.4 to 32.9 μg/l. Average rates of suicide mortality (per 100 000 capita) range between 0.790 (±0.198) and 123 (±50). About 16 original studies confirmed the inverse relationship between lithium concentrations in potable water and suicide mortality rates (R = -0.576; R2 = 0.3323; 95% CI, -0.820 to -0.325; β = -0.3.2; P = 0.019). High lithium concentrations in potable water were associated with decreased suicide rates. We concluded that lithium concentration in potable water was inversely associated with suicide mortality rates among a total population. However, further research is required to clarify the relationship between lithium concentrations in drinking water and suicide rate.

Warmer water, high light intensity, lithium and microplastics: Dangerous environmental combinations to zooplankton and Global Health?

Nowadays there is a high concern about the combined effects of global warming and emerging environmental contaminants with significant increasing trends of use, such as lithium (Li) and microplastics (MPs), both on wildlife and human health. Therefore, the effects of high light intensity (26,000 lx) or warmer water temperature (25 °C) on the long-term toxicity of Li and mixtures of Li and MPs (Li-MPs mixtures) were investigated using model populations of the freshwater zooplankton species Daphnia magna. Three 21-day bioassays were done in the laboratory at the following water temperatures and light intensities: (i) 20 °C/10830 lx; (ii) 20 °C/26000 lx (high light intensity); (iii) 25 °C/10830 lx (warmer temperature). Based on the 21-day EC50s on reproduction, high light intensity increased the reproductive toxicity of Li and Li-MPs mixtures by ~1.3 fold; warmer temperature increased the toxicity of Li by ~1.2 fold, and the toxicity of Li-MPs mixtures by ~1.4 fold based on the concentration of Li, and by ~2 fold based on the concentrations of MPs. At high light intensity, Li (0.04 mg/L) and Li-MPs mixtures (0.04 Li + 0.09 MPs mg/L) reduced the population fitness by 32 % and 41 %, respectively. Warmer temperature, Li (0.05 mg/L) and Li-MPs mixtures (0.05 Li + 0.09 MPs mg/L) reduced it by 63 % and 71 %, respectively. At warmer temperature or high light intensity, higher concentrations of Li and Li-MPs mixtures lead to population extinction. Based on the population growth rate and using data of bioassays with MPs alone done simultaneously, Li and MPs interactions were antagonistic or synergistic depending on the scenario. High light intensity and chemical stress generally acted synergistically. Warmer temperature and chemical stress always acted synergistically. These findings highlight the threats of long-term exposure to Li and Li-MPs mixtures to freshwater zooplankton and Global Health in a warmer world.

Lithium in Drinking Water as a Public Policy for Suicide Prevention: Relevance and Considerations

Although suicide is considered a major preventable cause of mortality worldwide, we do not have effective strategies to prevent it. Lithium has been consistently associated with lowering risk of suicide. This effect could occur at very low concentrations, such as trace doses of lithium in tap water. Several ecological studies and recent meta-analysis have suggested an inverse association between lithium in water and suicide in the general population, with a lack of knowledge of clinically significant side effects. This paper is aimed as a proposal to discuss the addition of lithium to drinking water to decrease the suicide rate. For this, we review the evidence available, use previous experiences, such as water fluoridation to prevent dental caries, and discuss the complexity involved in such a public policy. Considering the limited data available and the controversies contained in this proposal, we suggest that a consensus on lithium concentration in water is needed, where the suicide rates start to reduce, as happened with water fluoridation. This measure will require to develop community-controlled trials with strict monitoring of any side effects, where democratic procedures would constitute one of the most appropriate ways to validate its implementation according to the reality of each community.