No abstract

Golestan province in north Iran is known to be a high-risk area for esophageal cancer (EC). Of a long list of multiple risk factors, this study focuses on a possible link between the epidemiologic patterns of EC and the anomalous concentration of some ions and elements in the drinking water sources. A total of 183 samples from 45 villages covering a wide range of EC mortality rates are collected and analyzed. The results demonstrate that NO(3)(-), SO(4)(2-), Sb, and Sr exceed the recommended maximum concentration level (MCL) in drinking water. This is more prominent in the villages with high esophageal cancer mortality rate, suggesting a possible link between EC incidence and water quality. Se concentration in drinking water increases from low to the high EC areas, a finding contrary to the expected trend. It is concluded that Se deficiency does not play a major role in the etiology of EC in the Golestan province. The statistical results obtained from Mann-Whitney and Kruskal-Wallis tests along with cluster analysis are consistent with the observed trend of EC mortality rate in Golestan province.

Geochemical characteristics and arsenic content of groundwater in the Kurdistan and West Azerbaijan provinces (west of Iran) were analyzed. Groundwater is the local source of drinking water and travertine springs are mainly used for bathing and balneological purposes.The results indicate that total arsenic in travertine springs and groundwater range between 212 to 986.9 and 0.4 to 688.9 µg/L, respectively. Speciation of arsenic suggests arsenite the dominant arsenic species in travertine spring (68.2 to 98.9%). The variations of Br/Cl and B/Cl ratio, negative ORP (Oxygen Redox Potential) and high concentrations of Cl, Na, Cs, Li, Rb, Sr, B, Br and Rb in travertine spring samples confirm deep groundwater circulation in the volcanic basement. The results of saturation indices show that groundwater samples are supersaturated with respect to iron oxides, calcite, dolomite and aragonite and undersaturated with respect to gypsum and halite. In spite of gold mineralization, dissolution of arsenic-containing sulfide minerals is not the main source of arsenic contamination in groundwater. Spatial coincidence between the arsenic anomaly in groundwater and the travertine springs distribution illustrates they are the main source of arsenic in groundwater. The present study is useful in addressing future measures in groundwater resource management, in the volcanic regions in the west of Iran.

The presence and enrichment of heavy metals in dust depositions have been recognized as an emerging environmental health issues in the urban and industrial areas. In this study, the deposition of some metals was found in Qom, a city located in a semi-desert area in Iran that is surrounded by industrial areas. Dust deposition samples were collected using five sampling stations during a year. Dust samples were digested applying acidic condition and then, the metal content was analyzed using inductively coupled plasma technology (ICP-OES). Comparative results showed the following order, from the maximum to the minimum concentration (mg/kg dust) of elements: Ca > Al > Fe > Mg > Ti > Si > K > B > Sr > Mn > P > Ba > Cr > Zn > Ni > Sn > Pb > V > Na > Cu > Co > U > Li > Ce > Ag. The differences among the average concentrations of metals in the five stations were not significant (p value > 0.05). The average concentration of some metals increased significantly during cold seasons. In this study, the cluster analysis (CA) and princicipal component analysis (PCA) were applied, and relationships among some elements in different clusters were found. In addition, the geo-accumulation and enrichment analysis revealed that the following metals had been enriched more than the average values: boron, silver, tin, uranium, lead, zinc, cobalt, chromium, lithium, nickel, strontium, and coper. The presence of thermal power plant, pesticide manufacturing plants, publishing centers, traffic jam, and some industrial areas around the city has resulted in the enrichment of some metals (particularly in cold seasons with atmospheric stable conditions) in dust deposition.

No abstract