Possible involvement of overexposure to environmental selenium in the etiology of amyotrophic lateral sclerosis: a short review.

Excess exposure to the metalloid selenium (Se), a trace element with both toxicologicaland nutritional properties, has been implicated in the etiology of a human motor neuron diseaseof unknown origin and extremely severe prognosis, sporadic amyotrophic lateral sclerosis (ALS).This relation has been suggested on the basis of two epidemiologic investigations which found anincreased risk of ALS associated with residence in a seleniferous area or with consumption of drinkingwater with unusually high levels of inorganic hexavalent Se, in South Dakota and in northernItaly respectively. Biological plausibility to a Se-ALS relation is provided by veterinary medicineobservations and toxicological studies, showing that Se, particularly the inorganic forms, has a selectivetoxicity to motor neurons in swine and in cattle. Neurotoxic effects of Se species have also beendemonstrated in laboratory studies and, for the inorganic forms, even at very low concentrations.Selenium has also been shown to affect muscle function in experimental animal models. Overall,these findings from the epidemiologic and the toxicological literature indicate that environmental Se,particularly in its inorganic forms and at unexpectedly low levels of exposure, might be a risk factorfor ALS, suggesting the opportunity to further investigate this issue

Assessment of selenium and cadmium levels in serum and toenails: A cross-sectional study in Modena, Northern Italy.

Assessment of selenium and cadmium levels in serum and toenails: A cross-sectional study in Modena, Northern Italy

Selenium in humans: which is the safe range of intake?

Selenium in humans: which is the safe range of intake

Cadmium, lead and mercury levels in cerebrospinal fluid and risk of amyotrophic lateral sclerosis – A case-control study.

Cadmium, lead and mercury levels in cerebrospinal fluid and risk of amyotrophic lateral sclerosis – A case-control study

Selenium, zinc and copper content of foods consumed in an Italian community

This study aimed to determine the concentrations of selenium, zinc and copper in foods generally composing the diet of Northern Italy population in order to implement a database of the quantitative content for each of the three trace elements, according to food category intake. Food samples were collected from (small to large) distribution markets in triplicates and trace elements determination was performed with ICP-MS after sample mineralization. We found the highest levels of selenium in meat (202g/kg), fish and seafood (489), dry fruits (314) and legumes (220). The level of zinc was higher in cereal products (11.7 mg/kg), meat (28.4), dairy products (18.8), legumes (21.2) and dry fruits (37.8). Finally, the highest concentration of copper was found in dry fruits (14.9 mg/kg), legumes (6.2), sweets (4.1) and meat (3.7). Our findings will allow to estimate dietary trace elements exposure which could be useful for both toxicological and epidemiological studies

Risk of Amyotrophic Lateral Sclerosis and Exposure to Particulate Matter from Vehicular Traffic: A Case-Control Study

(1) Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with still unknown etiology. Some occupational and environmental risk factors have been suggested, including long-term air pollutant exposure. We carried out a pilot case-control study in order to evaluate ALS risk due to particulate matter with a diameter of ≤10 µm (PM10) as a proxy of vehicular traffic exposure. (2) Methods: We recruited ALS patients and controls referred to the Modena Neurology ALS Care Center between 1994 and 2015. Using a geographical information system, we modeled PM10 concentrations due to traffic emissions at the geocoded residence address at the date of case diagnosis. We computed the odds ratio (OR) and 95% confidence interval (CI) of ALS according to increasing PM10 exposure, using an unconditional logistic regression model adjusted for age and sex. (3) Results: For the 132 study participants (52 cases and 80 controls), the average of annual median and maximum PM10 concentrations were 5.2 and 38.6 µg/m3, respectively. Using fixed cutpoints at 5, 10, and 20 of the annual median PM10 levels, and compared with exposure <5 µg/m3, we found no excess ALS risk at 5-10 µg/m3 (OR 0.87, 95% CI 0.39-1.96), 10-20 µg/m3 (0.94, 95% CI 0.24-3.70), and ≥20 µg/m3 (0.87, 95% CI 0.05-15.01). Based on maximum PM10 concentrations, we found a statistically unstable excess ALS risk for subjects exposed at 10-20 µg/m3 (OR 4.27, 95% CI 0.69-26.51) compared with those exposed <10 µg/m3. However, risk decreased at 20-50 µg/m3 (OR 1.49, 95% CI 0.39-5.75) and ≥50 µg/m3 (1.16, 95% CI 0.28-4.82). ALS risk in increasing tertiles of exposure showed a similar null association, while comparison between the highest and the three lowest quartiles lumped together showed little evidence for an excess risk at PM10 concentrations (OR 1.13, 95% CI 0.50-2.55). After restricting the analysis to subjects with stable residence, we found substantially similar results. (4) Conclusions: In this pilot study, we found limited evidence of an increased ALS risk due to long-term exposure at high PM10 concentration, though the high statistical imprecision of the risk estimates, due to the small sample size, particularly in some exposure categories, limited our capacity to detect small increases in risk, and further larger studies are needed to assess this relation

Correlation between cadmium and selenium blood levels in an Italian population.

Correlation between cadmium and selenium blood levels in an Italian population