Impacts of Trace Metal Pollution in the Ship Breaking Areas, Chattagram, Bangladesh

Abstract

The current investigation indicates possible trace metal accumulation in groundwater, sea water and sediments due to ship breaking activity along the coast of Bay of Bengal in Sitakund Upazilla, Chattogram, Bangladesh. Sediment were collected from the ship-breaking industrial region of Bangladesh, and eleven trace metals (Cd, Cr, Fe, Mn, Cu, Ni, Co, Zn, As, Pb, and Ag) were measured by an atomic absorption spectrometer. The goal was to determine origin, the extent of sediment contamination, their regional distributions, and associated ecological and human health hazards. This study found considerable quantities of Pb, Cd, Mn, Zn, and Cu when compared the analyzed trace metals with standards. The results of indices e.g. enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF) and nemerow integrated pollution index (NIPI) showed nearly all of the sediment samples had high levels of Pb, Cd, Zn, Cu, As, and Ag contamination. The pollution load index (PLI) and total toxic unit (TU) values divulged that most of the sediments were highly polluted. Spatial distribution maps indicate that trace metals were predominantly deposited in the northern and southern parts of the region rather than the central part. While the highest health index (HI) values for Mn, Pb, Cr, As, Fe, Cu, Ni, and Co for children were close to the threshold value and the HI values of Zn for both adults and children were higher than the safe limit, all other HI values for adults, with the exception of Zn, were below this limit. For children, the mean total carcinogenic risk (TCR) values of Cr, As, and Ni exceeded the permissible threshold, whereas for adults, the mean TCR values of Ni above the permissible level. The cancer risk possibilities in three pathways were further assessed using Monte Carlo simulation which demonstrated long term exposure of these metals escalated the probabilities of carcinogenic risk. The majority of trace metals have anthropogenic origins, which was attributed to ship breaking activities, based on Pearson correlation matrix, principal component analysis, and cluster analysis. Moreover, the concentrations of eleven trace metals (Pb, Cd, Cr, Fe, Mn, Zn, Cu, Ni, Co, As and Ag) were assessed in both groundwater and seawater collected from the ship breaking industrial area of Bangladesh using an atomic absorption spectrometer. The investigation aimed to estimate the water quality and pollution level employing several indices, and its associated health risks for the first time in that area. This study found that Cd, Cr, Fe, Pb, Mn, and Ni were higher in both groundwater and seawater compared with WHO standards. Based on the WQI (Water Quality Index) and EWQI (Entropy Water Quality Index) classifications, the quality of most of the groundwater is extremely poor or unsuitable for drinking purposes. Furthermore, the HPI (Heavy Metal Pollution Index), HEI (Heavy Metal Evaluation Index), and CD (Degree of Contamination) values of most groundwater and all seawater samples exhibit a higher degree of pollution. In addition, the results of NI (Nemerow Pollution Index) come to an end that both groundwater and seawater in the study area are mostly polluted by Fe, Mn, Pb, Cr and Cd. Although the HI (Hazard Quotient Index) values of almost all studied trace metals in both cases of adults and children are within the safe limit, the HI value of Cr for an adult is near the threshold limit and the maximum HI value of Cr for children exceeds this limit. The carcinogenic risk reveals that Cr, Pb, As and Cd produce detrimental effects on local people through the direct ingestion of groundwater. The pollution source is identified using principal component analysis and a Pearson correlation matrix as being primarily anthropogenic and attributed to intensive ship breaking activities or other industries in the area. In addition, the study examined the amounts of trace metals in human bodies and their geographical distribution by analyzing hair and nails samples from individuals who either live near the ship breaking industrial region or are involved in ship breaking operations. Comparing hair and nail samples to other researchs, high concentrations of trace metals were found. Male participants showed considerably greater amount of Pb, Cd, Cr, Ni, Co, Fe, and Zn in their hair and Cd, Cr, Ni, Fe, Zn, and Mn in their nail samples than female participants. This suggests that males are more exposed to these metals because they work in the ship breaking industry more frequently and intensely. Additionally, hair samples and nail samples from ship breaking workers had much greater concentrations of Pb, Cd, Cr, Ni, Cu, Fe, and Zn than those detected in the local population. While the mean concentrations of several hazardous metals, including Pb, Cd, As, Co, and Be, in nail samples show a positive correlation with age, there is no apparent connection between the trace metal contents in hair samples and age. The spatial distribution maps demonstrate that the unions of Bhatiari, Sonaichhari, and Banshbaria have the highest amounts of the majority of the trace metals. The findings for the Se/trace metal molar ratio indicate the potential of toxicity for each trace metal under study. Yet, Se has the ability to detoxicated most of the human body's Cd. The bulk of these trace metals have anthropogenic origins mostly related to ship breaking activities, according to observations from principal component analysis and Pearson correlation matrix.