Heavy metal contamination is a globally recognized environmental issue, threatening human life very seriously. Increasing population and high demand for food resulted in release of various contaminants into environment that finally contaminate the food chain. Edible plants are the major source of diet, and their contamination with toxic metals may result in catastrophic health hazards. Heavy metals affect the human health directly and/or indirectly; one of the indirect effects is the change in plant nutritional values. Previously, a number of review papers have been published on different aspects of heavy metal contamination. However, no related information is available about the effects of heavy metals on the nutritional status of food plants. This review paper is focused upon heavy metal sources, accumulation, transfer, health risk, and effects on protein, amino acids, carbohydrates, fats, and vitamins in plants. The literature about heavy metals in food plants shows that both leafy and nonleafy vegetables are good accumulators of heavy metals. In nonleafy vegetables, the bioaccumulation pattern was leaf > root ≈ stem > tuber. Heavy metals have strong influence on nutritional values; therefore, plants grown on metal-contaminated soil were nutrient deficient and consumption of such vegetables may lead to nutritional deficiency in the population particularly living in developing countries which are already facing the malnutrition problems.

The uptake and bioaccumulation of heavy metals by food plants, their effects on plants nutrients, and associated health risk: a review.

Soil contamination with cadmium, consequences and remediation using organic amendments

Comprehensive review on phytotechnology: Heavy metals removal by diverse aquatic plants species from wastewater

Research on aerosol sources and chemical composition: Past, current and emerging issues

Environmental pollution of electronic waste recycling in India: A critical review.

The present investigation deals with the accumulation of heavy metals in fields contaminated with fly ash from a thermal power plant and subsequent uptake in different parts of naturally grown plants Results revealed that in the contaminated site, the mean level of all the metals (Cd, Zn, Cr, Pb, Cu, Ni, Mn and Fe) in soil and different parts (root and shoots) of plant species were found to be significantly (p Fe (188) > Ni (158) > Pb (142) > Zn (131) > Mn (127) > Cr (111) > Cu (110) Whereas, enrichment factor of metals in root and shoot parts, were found to be in the order of Cd (756) > Fe (475) > Zn (279) > Ni (222) > Cu (169) > Mn (153) > Pb (131) > Cr (102) and Cd (606) approximately equal Fe (606) > Zn (265) > Ni (257) > Mn (219) > Cu (158) > Pb (137) > Cr (101) respectively In contaminated site, translocation factor (TF) of metals from root to shoot was found to be in the order of Mn (138) > Fe (127) > Pb (103) > Ni (094) > Zn (085) > Cd (082) > Cr (073) and that of the metals Cd with Cr, Cu, Mn, Fe; Cr with Pb, Mn, Fe and Pb with Fe were found to be significantly correlated The present findings provide us a clue for the selection of plant species, which show natural resistance against toxic metals and are efficient metal accumulators

Accumulation and translocation of heavy metals in soil and plants from fly ash contaminated area.

The present study deals with the effect of fireworks on ambient air quality during Diwali Festival in Lucknow City. In this study, PM10, SO2, NOx and 10 trace metals associated with PM10 were estimated at four representative locations, during day and night times for Pre Diwali (day before Diwali) and Diwali day. On Diwali day 24 h average concentration of PM10, SO2, and NOx was found to be 753.3, 139.1, and 107.3 μg m−3, respectively, and these concentrations were found to be higher at 2.49 and 5.67 times for PM10, 1.95 and 6.59 times for SO2 and 1.79 and 2.69 for NOx, when compared with the respective concentration of Pre Diwali and normal day, respectively. On Diwali day, 24 h values for PM10, SO2, and NOx were found to be higher than prescribed limit of National Ambient Air Quality Standard (NAAQS), and exceptionally high (7.53 times) for PM10. On Diwali night (12 h) mean level of PM10, SO2 and NOx was 1,206.2, 205.4 and 149.0 μg m−3, respectively, which was 4.02, 2.82 and 2.27 times higher than their respective daytime concentrations and showed strong correlations (p Fe (747.23)>Zn (542.62)>Cu (454.03),>Pb (307.54)>Mn (83.90)>Co (78.69)>Cr (42.10)>Ni (41.47)>Cd (34.69) in ng m−3 and all these values were found to be higher than the Pre Diwali (except Fe) and normal day. The metal concentrations on Diwali day were found to be significantly different than normal day (except Fe & Cu). The concentrations of Co, Ni, Cr and Cd on Diwali night were found to be significantly higher than daytime concentrations for Pre Diwali (control). The inter correlation of metals between Ca with Pb, Zn with Ni and Cr, Cu with Co, Co with Mn, Ni with Cd, Mn with Cd, Ni with Cd and Cr, and Cr with Cd showed significant relation either at p<0.05 or P<0.01 levels, which indicated that their sources were the same. The metals Cu, Co, Ni, Cr and Cd showed significant (p<0.01) association with PM10. These results indicate that fireworks during Diwali festival affected the ambient air quality adversely due to emission and accumulation of PM10, SO2, NOx and trace metals.

Ambient air quality of Lucknow City (India) during use of fireworks on Diwali Festival

Urban populations are exposed to a high level of fine and ultrafine particles from motor vehicle emissions which affect human health. To assess the hourly variation of fine particle (PM 2.5 ) concentration and the influence of temperature and relative humidity (RH) on the ambient air of Lucknow city, monitoring of PM 2.5 along with temperature and RH was carried out at two residential locations, namely Vikas Nagar and Alambagh, during November 2005. The 24 h mean PM 2.5 concentration at Alam-bagh was 131.74 μg/m 3 and showed an increase of 13.74%, which was significantly higher (p < 0.05) than the Vikas Nagar level. The 24 h mean PM 2.5 on weekdays for both locations was found to be 142.74 μg/m 3 (an increase of 66.23%) which was significantly higher (p < 0.01) than the weekend value, indicating that vehicular pollution is one of the important sources of PM 2.5 . The mean PM 2.5 at night for all the monitoring days was 157.69 μg/m 3 and was significantly higher (p < 0.01) than the daytime concentration (89.87 μg/m 3 ). Correlation and multiple regressions showed that the independent variables, i.e., time, temperature, and RH together accounted for 54%, whereas RH alone accounted for 53% of total variations of PM 2.5 , suggesting that RH is the best influencing variable to predict the PM 2.5 concentration in the urban area of Lucknow city. The 24 h mean PM 2.5 for all the monitoring days was found to be higher than the NAAQS recommended by the US-EPA (65 μg/m 3 ) and can be considered to be an alarming indicator of adverse health effects for city dwellers.

Fine Particles (PM2.5) in Residential Areas of Lucknow City and Factors Influencing the Concentration

The present study deals with the assessment of ambient air quality with respect to respirable suspended particulate matter (RSPM or PM10 < or = 10 microm) and trace metals (Fe, Zn, Cu, Cr Ni, Cd, Mn and Pb) concentrations in RSPM at five locations of Renukoot, an industrial area of Eastern Uttar Pradesh. The 24 hr mean concentrations of PM10 ranged between 69.3 to 118.9 microg m(-3), which is well within the permissible limit (150 microg m(-3)) of national ambient air quality standards (NAAQS) but found higher than the prescribed annual daily limit of US EPA (50 microg m(-3)). The ambient air was mostly dominated by the Fe and least by the Cd among the metal analysed. Murdhawa, a commercial place influenced by vehicular population, is found to be the most polluted area of Renukoot and Dongia nalla (forest area) the least. The ambient air of Murdhawa is rich in Cu and Ni, indicating contribution of mobile sources. The Rammandir a residential place near the industry, is rich in Cd and Cr suggesting contribution of point sources. The Ni concentration is found to be alarmingly high in the air at all the locations except Dongia nallah, when compared with the EC (European Commission) limit (20 ng m(-3)). The Cd concentration is found to be higher only at Rammandir as compared with the EC limit (5 ng m(-3)). Mean concentrations of Zn, Pb and Mn are found to be almost equal in the ambient air of all the locations, suggesting the significance of sources contributing to presence of these metals. Zn, Cu, Pb and Ni having a significant correlation with PM10 indicate the same source contributing these metals as well as PM10. The present study has focused on the quantitative variation in different metals in the PM10, which is extremely harmful due to their toxic and carcinogenic nature.

Metals concentration associated with respirable particulate matter (PM10) in industrial area of Eastern U.P. India.

A simple, quantification of the inhibitory effects of Cu & Cd on germination and root elongation of mung (var. K-851) and gram (var. Uday), was carried out. From the data obtained in the presence of different concentration of metals, Germination Index (GI), Metal Tolerance Index (MTI), and Percent Phytotoxicity was calculated. Results showed that both the plants species had a reduced seed germination and root growth with increasing concentration of both the selected metals. In treated samples, maximum germination recorded was 98.8 % (Cu) and 93.3 % (Cu) and the minimum was 57.7 % (Cd) and 17.7% (Cd) with mung and gram, respectively. The percent phytotoxicity was found in the range of 62.8 to 78.7 for Cu and 77.6 to 93.1 for Cd in case of gram whereas in case of mung percent phytotoxicity was found to be 85.0 to 96.0 and 79.5 to 89.5 for Cu and Cd respectively. The maximum metal tolerance index was found to be 37.16 (Cu) & 14.94 (Cu) and minimum was 6.76 (Cd) & 3.96 (Cu) for gram and mung respectively. The maximum germination index was found to be 3.2 (Cd) and 1.61 (Cu) and minimum was 0.11 (Cd) and 0.33 (Cu) for gram and mung respectively. These bio-assay techniques may be helpful in identifying the suitable tolerant and resistant plant species and toxicity assessment of contaminated water.

Ramesh Singh

Papers

Accumulation and translocation of heavy metals in soil and plants from fly ash contaminated area.

Ambient air quality of Lucknow City (India) during use of fireworks on Diwali Festival

Fine Particles (PM2.5) in Residential Areas of Lucknow City and Factors Influencing the Concentration

Metals concentration associated with respirable particulate matter (PM10) in industrial area of Eastern U.P. India.

Phytotoxicity of trace metals (Cu & Cd) to Gram (Cicer arientinum) and Mung (Phaseolus mungo)