Heavy metal enrichment and ecological risk assessment of surface sediments in Khorramabad River, West Iran.

The ecological health of rivers has often been threatened in urbanized catchments due to the expansion of industrial activities and the population growth. Khorramabad River which flows through Khorramabad city, west of Iran, is an example of such settings. The river water is used for agricultural purposes downstream. In this study, the effect of Khorramabad city on heavy metal and metalloid (Cu, Pb, Zn, Ni, Cr, and As) loads in Khorramabad River sediments was investigated. To evaluate sediment pollution and potential adverse biological effects, surface sediment samples were collected at selected locations along the river and were characterized for their geochemical properties. Contamination factor (CF), pollution load index (PLI), and ecological risk assessment (RI) were calculated. Also, sediment quality guidelines (SQGs) were used to screen contaminants of concern in the study area. The results showed that sediments were moderately polluted, with stations located in more densely populated areas showing higher pollution indicators. Copper, Zn, and Pb sources could be attributed to urban wastewater, whereas Ni, Cr, and As had both natural and anthropogenic sources. Moreover, ecological risk assessments showed that sediments could be classified in the category of low risk. The results of the present study showed the effect of anthropogenic activities on heavy metal loads of the river sediments and these findings can be used to mitigate potential impacts on the environment and human health.

Monitoring deterioration of vegetation cover in the vicinity of smelting industry, using statistical methods and TM and ETM(+) imageries, Sarcheshmeh copper complex, Central Iran.

Simple statistical methods on Normalized Difference Vegetation Index (NDVI) and bands 3 and 4 data of relatively coarse resolution Thematic Mapper (TM) and Enhanced Thematic Mapper plus (ETM(+)) imageries were used to investigate the impacts of air pollution on the deterioration of the vegetation cover in the Sarcheshmeh copper complex of central Iran. Descriptive statistics and k-means cluster analysis indicated that vegetation deterioration had already started in the prevailing wind directions. The results show that combination of simple statistical methods and satellite imageries can be used as effective monitoring tools to indicate vegetation stress even in regions of sparse vegetation. Despite various possible perturbing factors upon NDVI, this index remains to be a valuable quantitative vegetation monitoring tool.

Speciation and phytoavailability of heavy metals in contaminated soils in Sarcheshmeh area, Kerman Province, Iran.

Heavy metal content in soil and the most abundant indigenous plant species (Artemisia sieberi) in Sarcheshmeh area is investigated. Sequential extraction analysis is carried out and phytoavailable fractions of selected heavy metals are also determined. The results show that heavy metals in the study area are potentially bioavailable. Calculated transfer factor (mean value for Cu: 5.7; As: 8.9; Pb: 4.1; Mo: 7.2; Cd: 1.9; and Zn: 1.8) and heavy metal concentration in plant species indicate that metal contamination is already transferred to Artemisia sieberi which proved to behave like an accumulator plant and hence poses a serious threat to local population. Contamination is mostly the result of three decades of ore smelting at the Sarcheshmeh copper complex.