Baseline heavy metals in plant species from some industrial and rural areas: Carcinogenic and non-carcinogenic risk assessment

The first ecological contamination study of avian mercury and lead in southeast Iran, Hamun International Wetlands

The concentrations of mercury (Hg) and lead (Pb) in feather samples of nine bird's species (n = 65) were determined from southeastern areas of Iran, Hamun International Wetlands. Hg concentrations were ranged from 0.40 to 3.00 mg/kg dry wt and from 0.38 to 1.76 mg/kg for primary and secondary feathers, respectively. Furthermore, Pb concentrations were ranged from 1.43 to 4.10 mg/kg and from 1.28 to 3.65 mg/kg for primary and secondary feathers, respectively. Deposition of metals varied significantly among the primary and secondary feathers of systematic category (families) for Hg and Pb (p < 0.001). It was found that there is a significant difference in feather Hg and Pb concentrations across species (p < 0.001) with highest concentrations in saker falcon (Falconidae) (Hg = 3.00 mg/kg and Pb = 4.10 mg/kg, primary feather) followed by little owl (Strigidae). Grey francolin (Phasianidae) contained the least amount of Hg (0.40 mg/kg) and Pb (1.43 mg/kg) in primary feather. The results showed that the highest concentrations of heavy metals were related to carnivores. Fish predators, omnivores, and insectivores were examined at the next level of metal concentration, with herbivores having the lowest concentrations of lead (1.43 mg/kg) and mercury (0.40 mg/kg). Birds with an open grasslands feeding strategy had the highest mercury and lead concentration. The average value for Pb was on the border of harmful effects (4 mg/kg). The results of this study indicate that mercury levels are lower than the threshold level for reproductive and behavioral harm (5 mg/kg).

Evaluation of Trace Element and Heavy Metal Levels of Some Ethnobotanically Important Medicinal Plants Used as Remedies in Southern Turkey in Terms of Human Health Risk

Heavy metal accumulation in medicinal plants has increased dramatically in recent years due to agricultural and industrial activities leading to pollution of natural sources. This study is focused on the concentration of trace elements and heavy metals in aboveground parts of 33 medicinal plants from the Eastern Mediterranean of Turkey. Results showed that the Al concentrations varied between 4.368 and 1104.627, the B level varied between 47.850 and 271.479, Ca values ranged between 1971.213 and 22,642.895, Cd concentrations ranged between 0.011 and 0.651, Cr contents varied between 1.371 and 41.692, Cu values varied between 13.278 and 42.586, Fe concentrations varied between 20.705 and 1276.783, K levels ranged between 652.143 and 14,440.946, Mg concentrations varied from 336.871 to 1869.486, Mn contents varied between 46.383 and 849.492, Na concentrations varied between 167.144 and 3401.252, Ni values varied between 0.065 and 9.968, Pb levels ranged between 1.311 and 16.238, and Zn concentrations ranged between 67.250 and 281.954 mg kg^-1, respectively. Furthermore, Recommended Dietary Allowance (RDA) values for trace elements and estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) for heavy metals were calculated. The concentrations of heavy metals in some studied plants distributed in industrial and mining regions were found as slightly higher than the acceptable limits determined by WHO. Consequently, in order to prevent this heavy metal accumulation, when collecting medicinal aromatic plants, rural areas, close to clean rivers, or mountainous areas should be preferred, away from highway, mining, and industrial areas.

Multidimensional Scaling of the Mineral Nutrient Status and Health Risk Assessment of Commonly Consumed Fruity Vegetables Marketed in Kyrgyzstan

Intensive production of fruits and vegetables causes heavy metal accumulation. Consumption of this kind of foodstuff is a growing concern of the modern world with the additional distress of the supply of enough foodstuffs. To contribute to this global purpose, this research aimed to find out the mineral nutrient and heavy metal concentrations of commonly consumed fruity vegetables in Kyrgyzstan. Totally, ten different fruity type vegetables were collected from five different large bazaars of Kyrgyzstan. From these, 20 samples, including washed/unwashed rinds of vegetables, were quantified in terms of their B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn contents by using inductively coupled plasma-optical emission spectrometry (ICP-OES). The concentrations of the fruity vegetables were found in the following range: B (1.392-25.816), Ca (92.814-4095.466), Cd (0.007-0.086), Cr (0.009-0.919), Cu (0.351-8.351), Fe (4.429-126.873), K (920.124-10,135.995), Mg (61.973-879.085), Mn (1.113-78.938), Na (36.132-266.475), Ni (0.039-1.215), Pb (0.081-2.906), and Zn (1.653-87.107) (mg kg^-1). It was determined that red capia pepper was the vegetable having the highest daily nutritional value according to evaluation done in our study. Taking into account of the HI values, all of the vegetables analyzed were determined to be lower than the limit value of 1 that falls into acceptable limits in terms of being safe. Peppers demonstrated the highest variation in terms of the elemental content. The high Cr content rendered hot pepper risky for consumption by both genders regarding with CR, and in terms of CR, it has been observed that nickel contents being found in vegetables including tomatoes pose a moderate risk for consumption. Quite lower risk was detected in red/Brandy-wine tomatoes, eggplants, and cucumber for both genders. As most striking result in our study, the Brandy-wine type tomato was found to be healthiest (as well as safest) and nutritious vegetable looking from the viewpoint of consumption in Kyrgyzstan.

Heavy Metal Contaminations in Herbal Medicines: Determination, Comprehensive Risk Assessments, and Solutions

Heavy metal contamination in herbal medicines is a global threat to human beings especially at levels above known threshold concentrations. The concentrations of five heavy metals cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg) and copper (Cu) were investigated using Inductively Coupled Plasma Optical Mass Spectrometry (ICP-MS) with 1773 samples around the world. According to Chinese Pharmacopoeia, 30.51% (541) samples were detected with at least one over-limit metal. The over-limit ratio for Pb was 5.75% (102), Cd at 4.96% (88), As at 4.17% (74), Hg at 3.78% (67), and of Cu, 1.75% (31). For exposure assessment, Pb, Cd, As, and Hg have resulted in higher than acceptable risks in 25 kinds of herbs. The maximal Estimated Daily Intake of Pb in seven herbs, of Cd in five, of Hg in four, and As in three exceeded their corresponding Provisional Tolerable Daily Intakes. In total 25 kinds of herbs present an unacceptable risk as assessed with the Hazard Quotient or Hazard Index. Additionally, the carcinogenic risks were all under acceptable limits. Notably, As posed the highest risk in all indicators including Estimated Daily Intake, Hazard Index, and carcinogenic risks. Therefore further study on enrichment effect of different states of As and special attention to monitoring shall be placed on As related contamination.

Nanofiltration and microfiltration for the removal of chromium, total dissolved solids, and sulfate from water

This study was designed to evaluate the hybrid system performance of nanofiltration (NF) and microfiltration (MF) processes in removing the hexavalent chromium (Cr(VI)) and sulfate from water. To do so, we made a hybrid pilot, including 1 μm and 5 μm filters, sand filter, activated carbon filters, and a nanofilter. We studied the effects of various parameters on the removal of Cr(VI) from polluted water and drinking water such as pH, pressure, concentrations of chromium, concentrations of sulfate, and total dissolved solids (TDS). The selected parameters were as follows: pressure: 0.1-0.4 MPa, pH: 2–10, Cr(VI) concentration: 0.1–0.4 mg/l, and sulfate concentration: 40–500 mg/l. According to the results, the efficiency of chromium removal increased with increasing the pH, while increasing the pressure from 0.1 to 0.4 MPa decreased the removal rate of chromium. In addition, increasing the concentrations of sulfate led to a decreasing trend in the removal efficiency. According to the findings of the study, the hybrid pilot made is able to reduce the chromium and sulfate to the levels under the WHO standard (Cr(VI) = 0.05 mg/l and sulfate = 500 mg/l).

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The optimal conditions for removal of Cr(VI) included the initial chromium concentration of 0.1 mg/l, pressure of 0.1 Mpa, pH of 10, and the sulfate concentration of 40 mg/l.

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In general, the experimental results revealed that the fabricated hybrid system including MF, NF, sand filter, and carbon filter has the ability to remove chromium and sulfate from drinking water (tap water) at a rate of 99%.

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At sulfate concentration of 40 mg/l, the TDS elimination efficiency was 97.75% and increased by 99.87% as the concentration increased to 500 mg/l. The presence of sulfate ions increases the TDS in water.