The burden of heat-related mortality attributable to recent human-induced climate change.

Climate change affects human health; however, there have been no large-scale, systematic efforts to quantify the heat-related human health impacts that have already occurred due to climate change. Here, we use empirical data from 732 locations in 43 countries to estimate the mortality burdens associated with the additional heat exposure that has resulted from recent human-induced warming, during the period 1991-2018. Across all study countries, we find that 37.0% (range 20.5-76.3%) of warm-season heat-related deaths can be attributed to anthropogenic climate change and that increased mortality is evident on every continent. Burdens varied geographically but were of the order of dozens to hundreds of deaths per year in many locations. Our findings support the urgent need for more ambitious mitigation and adaptation strategies to minimize the public health impacts of climate change.

Seasonal variations in the optical characteristics of dissolved organic matter in glacial pond water.

Large amounts of dissolved organic matter (DOM) are stored in mountain glaciers. However, few researches have analysed the optical characteristics of DOM in surface waters fed by mountain glaciers and their seasonal variations. In a pond fed by a glacier we observed simultaneous decreases in the dissolved organic carbon, and increases in both absorbance at 254 nm and specific absorption coefficient (SUVA254) during the ice-free season 2015. This behaviour differs from the typical behaviour of lake/pond water in summer, and from the trends observed in a nearby pond not fed by a glacier. The trends of DOM properties, main ions and water stable isotopes at the glacier-fed pond could be attributed to transient modifications of the subglacial hydrological system. Flushing of previously isolated pools of subglacially stored water, containing terrestrial DOM derived from glacially-overridden soil and vegetation, would be driven by intense rainfall events during the melting season. These findings suggest that heavy rainfall events during the melting season have the capability to transiently modify the characteristics of DOM in a glacial pond. These events may be further exacerbated in the future, as summer rainfall events in the Alps are predicted to increase due to global warming.

Integrating environmental, entomological, animal, and human data to model the Leishmania infantum transmission risk in a newly endemic area in Northern Italy.

INTRODUCTION: Historically, leishmaniasis in Italy was constrained to areas with Mediterranean climate. In the last 20 years, sand fly vectors (Phlebotomus perniciosus), cases of canine leishmaniasis (CanL) and cases of human visceral leishmaniasis (VL) have been observed in Northern Italian regions, traditionally classified as cold areas unsuitable for sand fly survival. AIM: We aim to evaluate through a One-Health approach the risk of endemic transmission of Leishmania infantum in the Piedmont Region, Northern Italy. METHODS: We collected environmental, entomological, animal, and human data. We applied a geostatistical binomial model to map the probability of P. perniciosus presence in the study area, using selected environmental parameters as predictors. We evaluated the spatial relationship between the probability of P. perniciosus presence and the geographical distribution of CanL and VL cases observed between 1999 and 2013. RESULTS: Between 1999 and 2003, 142 sampling sets (17%) out of 839 resulted positive for P. perniciosus. Elevation, degree of slope, normalized difference vegetation index (NDVI) and summer temperatures were associated with positive sampling sets. During the study period, 164 (13.6%) of Piedmont municipalities reported at least one autochthonous case of CanL, while 89 VL cases were observed in 54 municipalities (4.5%). We observed an association between municipalities affected by autochthonous CanL cases and the estimated probability of P. perniciosus presence (Odds Ratio for 10% increase of probability: 2.66; 95% confidence intervals (CI): 2.16-3.37). We found that human VL incident cases were positively associated with the probability of the municipality of residence of being endemic for CanL (Incidence Rate Ratio for 10% increase of probability: 1.49; 95% CI 1.02-2.16). CONCLUSIONS: Using a One-Health approach, we quantified the spatial association between the distribution of P. perniciosus, municipalities endemic for CanL and incident cases of human VL, suggesting that the disease has become endemic in the Piedmont region.

Seasonality of suicide: a multi-country multi-community observational study.

AIMS: We aimed to investigate the heterogeneity of seasonal suicide patterns among multiple geographically, demographically and socioeconomically diverse populations. METHODS: Weekly time-series data of suicide counts for 354 communities in 12 countries during 1986-2016 were analysed. Two-stage analysis was performed. In the first stage, a generalised linear model, including cyclic splines, was used to estimate seasonal patterns of suicide for each community. In the second stage, the community-specific seasonal patterns were combined for each country using meta-regression. In addition, the community-specific seasonal patterns were regressed onto community-level socioeconomic, demographic and environmental indicators using meta-regression. RESULTS: We observed seasonal patterns in suicide, with the counts peaking in spring and declining to a trough in winter in most of the countries. However, the shape of seasonal patterns varied among countries from bimodal to unimodal seasonality. The amplitude of seasonal patterns (i.e. the peak/trough relative risk) also varied from 1.47 (95% confidence interval [CI]: 1.33-1.62) to 1.05 (95% CI: 1.01-1.1) among 12 countries. The subgroup difference in the seasonal pattern also varied over countries. In some countries, larger amplitude was shown for females and for the elderly population (≥65 years of age) than for males and for younger people, respectively. The subperiod difference also varied; some countries showed increasing seasonality while others showed a decrease or little change. Finally, the amplitude was larger for communities with colder climates, higher proportions of elderly people and lower unemployment rates (p-values < 0.05). CONCLUSIONS: Despite the common features of a spring peak and a winter trough, seasonal suicide patterns were largely heterogeneous in shape, amplitude, subgroup differences and temporal changes among different populations, as influenced by climate, demographic and socioeconomic conditions. Our findings may help elucidate the underlying mechanisms of seasonal suicide patterns and aid in improving the design of population-specific suicide prevention programmes based on these patterns.

Influence of permafrost, rock and ice glaciers on chemistry of high-elevation ponds (NW Italian Alps).

Permafrost degradation, rock-glacier thawing, and glacier retreat are influencing surface water quality at high elevations. However, there is a lack of knowledge on the dominant geochemical reactions occurring in different cryospheric conditions and how these reactions change during the ice-free season. In the Col d'Olen area (LTER site, NW Italian Alps), four ponds with similar sizes, located in basins with different cryospheric features (glacier, permafrost, rock glacier, none of these), are present in a geographically limited area. All ponds were sampled weekly in 2015 and partially in 2014. Major ions, selected trace elements, and biotic parameters (dissolved organic carbon-DOC, fluorescence index-FI, and nitrate) are examined to evidence the effect of different cryospheric features on water characteristics. Where cryospheric conditions occur chemical weathering is more intensive, with strong seasonal increase of major ions. Sulphide oxidation dominates in glacier and permafrost lying on acid rocks, probably driven by enhanced weathering of freshly exposed rocks in subglacial environment and recently deglaciated areas, and active layer thickness increase. Differently, carbonation dominates for the rock glacier lying on ultramafic rocks. There, high Ni concentrations originate from dissolution of Mg-bearing rocks in the landform. In all settings, pH neutralisation occurs because of the presence of secondary carbonate lithology and ultramafic rocks. Nitrate highest concentrations and changes occur in cryospheric settings while DOC and FI do not show strong differences and seasonal variations. The establishment of more frequent monitoring for water quality in high-elevated surface waters is necessary to provide greater statistical power to detect changes on longer time scales.