Assessment of metal along a contamination gradient in soils collected from industrial areas in Northern Tunisia

COMInternational audienceMany studies were interested in the assessment and the monitoring of soil contamination with heavy metals. The aim of this study was to evaluate the effects of emissions from the Tunisian Steel Company El Fouladh in Bizerte (Tunisia). In this context, we measured Zinc (Zn), Copper (Cu), Lead (Pb) and Cadmium (Cd) soil’s concentrations from 8 sites along a contamination gradient. Besides, physicochemical parameters, pH, organic carbon, CEC and CaCO3 were measured. Heavy metals were determined using an atomic absorption spectrome-try. The results revealed a high concentration of heavy metals in soils collected from several sites. The contamination factor (CF) was determined to estimate soil contamination of the sam-pling sites, and revealed that the level of contamination varied along a contamination gradient, which may be due to the mobility of pollution

Dust metal loadings and the risk of childhood acute lymphoblastic leukemia

We evaluated the relationship between the risk of childhood acute lymphoblastic leukemia (ALL) and levels of metals in carpet dust. A dust sample was collected from the homes of 142 ALL cases and 187 controls participating in the California Childhood Leukemia Study using a high volume small surface sampler (2001–2006). Samples were analyzed using microwave-assisted acid digestion in combination with inductively-coupled plasma mass spectrometry for arsenic, cadmium, chromium, copper, lead, nickel, tin, tungsten, and zinc. Eight metals were detected in at least 85% of the case and control homes; tungsten was detected in less than 15% of homes. Relationships between dust-metal loadings (μg metal per m(2) carpet) and ALL risk were modeled using multivariable logistic regression, adjusting for the child’s age, sex, and race/ethnicity and confounders, including household annual income. A doubling of dust-metal loadings was not associated with significant changes in ALL risk [odds ratio (95% confidence interval): arsenic: 0.94 (0.83, 1.05), cadmium: 0.91 (0.80, 1.04), chromium: 0.99 (0.87, 1.12), copper: 0.96 (0.90, 1.03), lead: 1.01 (0.93, 1.10), nickel: 0.92 (0.80, 1.07), tin: 0.93 (0.82, 1.05), and zinc: 0.91 (0.81, 1.02)]. Our findings do not support the hypothesis that metals in carpet dust are risk factors for childhood ALL