Evaluation of Heavy Metals Concentration in Jajarm Bauxite Deposit in Northeast of Iran Using Environmental Pollution Indices

Abstract

Heavy metals are known as an important group of pollutants in soil. Major sources of heavy metals are modern industries such as mining. In this study, spatial distribution and environmental behavior of heavy metals in the Jajarm bauxite mine have been investigated. The study area is one of the most important deposits in Iran, which includes about 22 million tons of reserve. Contamination factor (CF), the average concentration (AV), the enrichment factor (EF) and geoaccumulation index (GI) were factors used to assess the risk of pollution from heavy metals in the study area. Robust principal component analysis of compositional data (RPCA) was also applied as a multivariate method to find the relationship among metals. According to the compositional bi-plots, the RPC1 and RPC2 account for 57.55% and 33.79% of the total variation, respectively. The RPC1 showed positive loadings for Pb and Ni. Also, the RPC2 showed positive loadings for Cu and Zn. In general, the results indicated that mining activities in the bauxite mine have not created serious environmental hazards in the study area except for lead and nickel. Finding potential relations between mining work and elevated heavy metals concentrations in the Jajarm bauxite mine area necessitates developing and implementing holistic monitoring activities. KEYWORDSEnvironmental behavior, Contamination criteria, Heavy metals, Multivariate statistical analyses, Jajarm bauxite deposit. MATERIALS AND METHODS Study AreaThe Jajarm bauxite deposit is the largest deposit in Iran and located in North Khorasan Province (northeast Iran) and 15 km North-East Jajarm town. The deposit is situated in 56 • 27' 30" longitude and 37 • 2' to 37 • 4' latitude ( Fig.1) and is more than 8 km long and 20 m thick and has over 22 million tons of storage. This region has a dry desert climate and low Malaysian Journal of Geosciences (MJG)

Accumulation of essential (copper, iron, zinc) and non-essential (lead, cadmium) heavy metals in Caulerpa racemosa, sea water, and marine sediments of Bintan Island, Indonesia

“…In addition, the open land of former bauxite mining on Bintan Island is a source of contamination of these metals in the waters. According to Rezaei et al (2019) and Ismail et al (2019), bauxite waste is a source of Fe and Zn metal contamination in the environment. 53,54 It is one of the causes of the high concentration of Zn and Fe metals in the research location.…”

Assessment of Heavy Metals Contamination in Surface Soils in Meiduk Copper Mine Area, Se Iran

“…The enrichment factor (EF) compares the concentration of an element in samples with the concentration of the same element in the noncontaminated area (i.e. geological background) [8]. The concept of EF was developed in the early 70's to identify the origin of elements in the atmosphere, precipitation or seawater.…”

“…The pollution load index is a measure of the degree of overall contamination in a sample station [8]. The pollution load index is calculated using equation 5:…”

“…A soil pollution assessment becomes very complex when different sources of contamination are present and their products are variably distributed. In these cases, the spatial variability of heavy metal concentrations in soils is basic information for identifying the possible sources of contamination and to delineate the strategies of site remediation [8]. In this research, spatial distribution map of heavy metals (Pb, Ni, Se, Mo and Zn) using the ordinary inverse distance weighting (IDW) method is created in the study area based on raw samples.…”

“…The impact of the mining industry on the environment has been a public concern and has increased awareness of the possible harmful effects of the industry. As an anthropogenic activity, mining has facilitated the movement and distribution of heavy metals in natural formations and anthropogenic activities may change the geochemical distribution of heavy metals more than the lithogenic resources [8,9]. Thus, environmental protection against various pollutants, such as heavy metals formed by industries, mines and modern technologies, is a concern for regulators, researchers as well as different industries.…”