Health risk assessment according to exposure with heavy metals and physicochemical parameters; water quality index and contamination degree evaluation in bottled water

This survey analysed 71 bottled water brands in Tehran, Iran. The laboratory analysis was investigated for ten physicochemical parameters and 16 elements, including heavy metals comprising (bicarbonate, fluoride, chloride, nitrate, nitrite, sulphate, pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), Na, Mg, Ca, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sr, Ba, and, Zn). Statistical analysis were performed with R software. The water quality index (WQI) approach was applied to investigate water quality, the carcinogen risk (CR) and hazard index (HI) methods were used for assessing the health risks, and the cumulative impacts of heavy metals were evaluated with contamination degree (C-d) and heavy metal evaluation index (HEI). The results showed that among the physicochemical parameters, EC, TDS, TH, and HCO3 and heavy metals like Sr > Zn > Cu > Ni had the Highest values. The WQI value in totals was 91.86 and had good quality class, and the order was good (60.56%), poor (35.21%), and very poor bottled water (4.22%). The correlation results demonstrated that WQI similar to Fe and Zn similar to Mn had significant correlation coefficients (r = 1). Moreover, there is a significant correlation between TH with Mg and Ca and also between HCO3 with EC, TH, and Ca, and then between SO4 with Na. Carcinogen risk for Cr in children and adults was 2 x 10(-4) and 6 x 10(-4,) respectively. The responsible pollutants in non-carcinogen risk assessment were F and NO3, and their HI was greater than one in adult and child subgroups. The values of Cd and HEI were lower than critical limits. Also, Pb had a significant correlation with Cd and HEI (r = 1). This study revealed that bottled water contains minerals and may possess heavy metals, which pose significant human health risks, especially for children.

Automated summary

This survey analyzed 71 bottled water brands in Tehran, Iran, examining their physicochemical parameters and heavy metal contents. The study utilized statistical analysis and various indices to assess water quality and health risks. The results indicated that the bottled water had good overall quality, but contained high levels of heavy metals, posing significant risks to human health, particularly for children.