Heavy metal pollution levels and health risk assessment of dust storms in Jazmurian region, Iran.

The Jazmurian basin in Iran is an area affected by climate change and desertification where aerosols and dust storms are common. The aim of this work was to determine the human and ecological risks from atmospheric particles during dust storms in different cities in the Jazmurian basin. For this purpose, the dust samples were collected from Jiroft, Roodbar Jonoob, Ghaleh Ganj, Kahnooj and Iranshahr cities, which are located around the Jazmurian playa in southeast of Iran. Satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products and the Aerosol Optical Depth (AOD) were used to detect aerosol loading in the atmosphere. Moreover, the trace element composition of the collected particles was determined and used to evaluate human and ecological impact assessment using US EPA human health risk assessment and ReCiPe 2016 endpoint hierarchist impact assessment method incorporated in the OpenLCA 1.10.3 software. The human health risk assessment of the particles revealed high non-carcinogenic risks for children from exposure to nickel and manganese and carcinogenic risks in both adults and children due to hexavalent chromium, arsenic and cobalt during dust storm events. Terrestrial ecotoxicity was found to have the largest ecological impact on ecosystems with copper, nickel and zinc exhibiting the largest contributions.

The efficiency of the Standardized Evapotranspiration Deficit Index (SEDI) in assessing the impact of drought on vegetation cover.

It is important to choose an indicator that can optimally demonstrate the effects of drought intensity on soil moisture access, evapotranspiration and the changes in vegetation cover at a regional scale. Therefore, herein, SEDI was developed by the fit of the experimental distribution of Gringorten on evapotranspiration deficit based on TerraClimate data at the time scales of 1, 3, 6 and 12 months, and its relationship with Standardized Precipitation-Evapotranspiration Index (SPEI), Standardized Precipitation Index (SPI), Standardized Soil Moisture Index (SSMI), Normalized Ecosystem Drought Index (NEDI) and Normalized Difference Vegetation Index (NDVI) were investigated. The results indicated that SEDI has the highest significant correlation (above 95%) with NEDI and SPEI, especially for the 1-month time scale. This index also revealed the lowest correlation (less than 25%) with SPI on short-term time scales. The relationship between SEDI and SSMI indicated the high sensitivity of SEDI to the cumulative reduction of low amounts of soil moisture. According to the findings, the 6-month SEDI with NDVI showed the highest correlation with a 1-month delay (r = 0.64) and the best fit between them occurred in wet months. However, in the dry months, the relationship between SEDI with NDVI was affected via water availability stresses, grazing intensity and pest infestation. Finally, the use of SEDI at a regional scale, especially in arid and semi-arid regions like Lorestan, could be recognized as an important index in depicting the effects of drought on vegetation cover, due to the use of the actual evapotranspiration factor.

Pollution and contamination assessment of heavy metals in the sediments of Jazmurian playa in southeast Iran.

Jazmurian playa was an ephemeral lake with a large catchment in southeast Iran, which dried up over the last 10 years as a result of prolonged drought. As the lake was recipient of incoming industrial water with trace metals deposited to the sediment, the dust is the cause of environmental concern of the region and requires evaluation and better management. The aim of this study was to evaluate the environmental and ecological pollution of Jazmurian playa. Hence, 24 collected surface sedimentary samples were analyzed with ICP-OES. The environmental pollution indices including degree of contamination (Cd), geoaccumulation index (Igeo), enrichment factor (EF), pollution load index (PLI) and potential ecological risk (PER) were determined. The study revealed moderately to strongly pollution levels of Pb, Ni and Al, while Dy, Pb, Y, Yb, Sm, Te, U, Cu, Mn, Sc represented moderate pollution. The EF values indicated four sites were highly enriched with Dy, Pb and Ni. The PER results showed high risk for four sites and considerable risk for others. Cluster analysis illustrated interconnection between the contaminants and the sites with major pollution at six sites. Obviously, climate change has considerable complex environmental impacts through transformation of local water and sediment pollution problem.