Assessment of the Heavy Metal Accumulation of Various Green Vegetables Grown in Nevsehir and their Risks Human Health.

This study aimed to investigate the accumulation of heavy metal in five different leafy green vegetables grown in 10 different agricultural lands in the province of Nevsehir, Turkey, and determine the human health risks that may arise as a result the consumption of such metals. The heavy metal concentrations found in the soil samples taken from the agricultural lands were as follows: manganese (Mn) > lead (Pb) > arsenic (As) > nickel (Ni) > copper (Cu) > cadmium (Cd). These concentrations were found to be well above the permitted limits imposed by the World Health Organization/Food and Agricultural Organization (WHO/FAO) and the United States Environmental Protection Agency (USEPA). Also, particularly the concentrations of Pb and As were found to be dangerous levels in the soil. According to their accumulation in the vegetables, the detected heavy metal concentrations were listed as Mn > Zn > Cu > Ni > As > Cd. The estimated daily intake amount of the heavy metals was also found to be higher than the limits determined by FAO/WHO. Furthermore, the target hazard quotient of the metals was Mn > As > Cu > Zn > Ni > Cd > Pb. It was found to be > 1 for the sampling areas, except for Cd and Pb. As a result of the study, it was determined that almost all of the annual heavy metal intake amount that the population living in this region should receive was met as a result of the consumption of leafy vegetables grown in the stations designated for this study. It is vital to effectively monitor the heavy metal in the soil and vegetables to reduce metal concentrations in the studied area and to investigate its effects on human health. By doing so, acute and chronic health problems due to the heavy metal exposure in this region can be prevented.

Growth and Lead Accumulation Capacity of Lemna minor and Spirodela polyrhiza (Lemnaceae): Interactions with Nutrient Enrichment.

A study to understand the biological effects of samples prepared with lead and the effects of lead were conducted on Lemna minor L. and Spirodela polyrhiza (L.) Schleid. This study was intended to test the hypothesis that nutrient enrichment (P, NO(3) (-)-N and SO(4) (2-)) enhances the metal tolerance of floating macrophytes. The plants were exposed to Pb concentrations 0, 1, 5, 10, 25, and 50 mg l(-1) for a period of 1, 3, 5, and 7 days. L. minor accumulated 561 mg g(-1) dry weight (dw) Pb, and S. polyrhiza accumulated 330 mg g(-1) dw Pb after 7 days, whereas in the groups enriched with nutrients, L. minor accumulated 128.7 mg g(-1) Pb and S. polyrhiza accumulated 68.7 mg g(-1) dw Pb after 7 days. Relative growth rates and photosynthetic pigments (chlorophyll a, b, and carotenoid) were measured in L. minor and S. polyrhiza exposed to different Pb concentrations under laboratory conditions. Relative growth rates were negatively correlated with metal exposure, but nutrient addition was found to suppress this effect. Photosynthetic pigment levels were found negatively correlated with metal exposure, and nutrient addition attenuated chlorophyll decrease in response to metal exposure. Metal and nutrient concentration in water decreased throughout the experiments. The study concluded that nutrient enrichment increases the tolerance of L. minor and S. polyrhiza to metals, that L. minor and S. polyrhiza are suitable candidates for the phytoremediation of low-level lead pollution, and that L. minor was more effective in extracting lead than was S. polyrhiza.

Verbascum bombyciferum Boiss. (Scrophulariaceae) as possible bio-indicator for the assessment of heavy metals in the environment of Bursa, Turkey.

In this study, we determined the heavy metal content (Cd(2+), Cr(3+), Cu(2+), Fe(3+), Ni(2+), Pb(2+), and Zn(2+)) in the soil surrounding the roots and different organs of Verbascum bombyciferum Boiss. (Scrophulariaceae), which is endemic to Uludag Mountain, Bursa, Turkey. Plant samples were collected from roadsides, and heavy metal accumulation capabilities were tested. This is one of the pioneer species of ruderal plant communities on roadsides, building sites, rubbish dumps, etc. Different organs of plant samples (roots, stems, leaves, and flowers) and their soils were analyzed by inductively couple plasma optical emission spectroscopy for their heavy metal contents. Some of the analyzed heavy metals (Cd(2+), Cr(3+), Pb(2+), and Zn(2+)) were usually increased depending on the traffic in the sample sites, and this variation was also reflected in heavy metal content of plant samples. Our results show that this plant can be used as a bio-indicator species in the monitoring of increased Cd(2+), Cr(3+), Pb(2+), and Zn(2+) in the environment. We also concluded that V. bombyciferum have the capability of Cd(2+), Cr(3+), Cu(2+), Ni(2+), Pb(2+), and Zn(2+) accumulation.