Limits...
Heavy metals in vegetables: screening health risks involved in cultivation along wastewater drain and irrigating with wastewater.

Sharma A, Katnoria JK, Nagpal AK - Springerplus (2016)

Bottom Line: Not just the crops irrigated with wastewater are hazardous, in present study, we have found that vegetables growing in vicinity of wastewater drain are also not safe for human consumption.Cadmium, a potential carcinogen was found in concentrations higher than permissible limits in many vegetables from all sites.Concentration of copper and lead in vegetable samples from different sites exhibited no statistically significant difference with respect to different sites.

View Article: PubMed Central - PubMed

Affiliation: Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab 143005 India.

ABSTRACT
Irrigation of agricultural land with wastewater leads to continuous buildup of metals at these sites which gets accumulated in the vegetables and crops growing on these sites. Not just the crops irrigated with wastewater are hazardous, in present study, we have found that vegetables growing in vicinity of wastewater drain are also not safe for human consumption. The risk associated with consumption of vegetables was assessed by calculating hazard quotient and results revealed that the hazard quotient for leafy and tuberous vegetables was higher than the safe limits in all the sites irrespective of mode of irrigation. Spinach was the most hazardous among all as the hazard quotient with respect to cobalt and copper was highest in spinach. Uptake trend of metals in all vegetables: Iron > Cobalt > Copper > Cadmium > Lead. Cadmium, a potential carcinogen was found in concentrations higher than permissible limits in many vegetables from all sites. Highest level of cadmium (1.20 mg/kg) and copper (81.33 mg/kg) was reported in site which was in vicinity of waste water drain but irrigated with ground water. Concentration of copper and lead in vegetable samples from different sites exhibited no statistically significant difference with respect to different sites.

No MeSH data available.


Content of copper in vegetables from different sites
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4837749&req=5

Fig4: Content of copper in vegetables from different sites

Mentions: Heavy metal contents in different vegetable samples from each site are represented in respective figures. Figure show the mean content of metal in each vegetable and maximum value reported among replicates. Uptake pattern of heavy metals by vegetables was found to be similar in all the sites. In all the three sites the uptake of metals exhibited the following trend: Iron > Cobalt > Copper > Cadmium > Lead. The concentration of all metals was found to be higher in the leafy and tuberous vegetables as compared to fruit vegetables with an exception of iron in vegetable samples from site 1. This trend was found to be in accordance with previous studies estimating heavy metals in vegetables (Arora et al. 2008; Singh et al. 2010). At Site 1 (irrigated with ground water but located across wastewater drain) uptake of cadmium was found to be maximum in fenugreek (0.8 mg/kg) followed by spinach (0.6 mg/kg). Cadmium is a possible carcinogen and dietary intake of cadmium affects kidneys and liver. Permissible limit for cadmium in bulb and fruits vegetables is 0.05 mg/kg, in leafy and tuberous vegetables is 0.1 mg/kg (FAO/WHO 2014). Mean concentration of cadmium in all samples from all sites was higher than permissible limits. Maximum concentration of cadmium (1.2 mg/kg) was reported in raddish samples from site irrigated with ground water (site 2). Site 2 (away from industrial discharge point) had lesser cadmium concentration in leafy vegetables as compared to those in site 1. At site 2 Turnip contained maximum content of Cd (0.87 mg/kg). Site 3 which is irrigated with wastewater showed maximum uptake of cadmium in turnip (1.06 mg/kg) followed by fenugreek (1 mg/kg) and raddish (0.8 mg/kg), as shown in Fig. 2. Accumulation of cobalt was maximum in spinach samples from both site 1 and site 3 (92 and 130.67 mg/kg, respectively), while being maximum in coriander samples (69 mg/kg) from site 2 (Fig. 3). Among all the sites, the least concentration of cobalt was reported in bulb vegetables. Cobalt though is an essential element, but its excess is known to cause phytotoxic effects in plant and interference in uptake of other essential elements (Nagajyoti et al. 2010). Human intake of higher concentrations of cobalt cause serious toxic effects which are attributed to its affinity to sulfhydryl group or because of antagonistic effects in calcium ion channel (Simonsen et al. 2011). The concentration of copper (80.33 mg/kg) was found highest in spinach samples of site 1 which is irrigated with ground water but growing in vicinity of wastewater drain (Fig. 4). Copper is also an essential element but its higher levels are known to cause toxicity effects and acute exposure (200 mg/kg) can lead to death (FAO/WHO 2011). Arora et al. (2008) has reported the concentration of copper in spinach in range of 15.9–17.4 mg/kg. In present study, it was observed that concentration of copper in ground water irrigated site (in vicinity of wastewater drain) was many folds higher than as reported by Arora et al. (2008). Iron was most accumulated metal among all plant samples. Mean concentration of Iron in samples from site 1 was maximum in bottle gourd (624 mg/kg) followed by fenugreek (612 mg/kg). In samples from site 2 and 3 maximum iron uptake was found in fenugreek (618 and 740 mg/kg). Minimum concentration of iron was reported in garlic samples from all sites (Fig. 5). Permissible concentration of lead in fruit, tuberous and bulb vegetables is 0.1 mg/kg, while that in leafy vegetables is 0.3 mg/kg (FAO/WHO 2014). It was observed mean content of lead in 7 out of 12 vegetable samples from site 3 was higher than permissible limit. Some vegetable samples from site 1 and 2 were found to contain lead higher than permissible limit (Fig. 6). The general trend of uptake of heavy metals revealed higher concentration of metals in leafy and tuberous vegetables as compared to fruits and bulbs.Fig. 2


Heavy metals in vegetables: screening health risks involved in cultivation along wastewater drain and irrigating with wastewater.

Sharma A, Katnoria JK, Nagpal AK - Springerplus (2016)

Content of copper in vegetables from different sites
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837749&req=5

Fig4: Content of copper in vegetables from different sites
Mentions: Heavy metal contents in different vegetable samples from each site are represented in respective figures. Figure show the mean content of metal in each vegetable and maximum value reported among replicates. Uptake pattern of heavy metals by vegetables was found to be similar in all the sites. In all the three sites the uptake of metals exhibited the following trend: Iron > Cobalt > Copper > Cadmium > Lead. The concentration of all metals was found to be higher in the leafy and tuberous vegetables as compared to fruit vegetables with an exception of iron in vegetable samples from site 1. This trend was found to be in accordance with previous studies estimating heavy metals in vegetables (Arora et al. 2008; Singh et al. 2010). At Site 1 (irrigated with ground water but located across wastewater drain) uptake of cadmium was found to be maximum in fenugreek (0.8 mg/kg) followed by spinach (0.6 mg/kg). Cadmium is a possible carcinogen and dietary intake of cadmium affects kidneys and liver. Permissible limit for cadmium in bulb and fruits vegetables is 0.05 mg/kg, in leafy and tuberous vegetables is 0.1 mg/kg (FAO/WHO 2014). Mean concentration of cadmium in all samples from all sites was higher than permissible limits. Maximum concentration of cadmium (1.2 mg/kg) was reported in raddish samples from site irrigated with ground water (site 2). Site 2 (away from industrial discharge point) had lesser cadmium concentration in leafy vegetables as compared to those in site 1. At site 2 Turnip contained maximum content of Cd (0.87 mg/kg). Site 3 which is irrigated with wastewater showed maximum uptake of cadmium in turnip (1.06 mg/kg) followed by fenugreek (1 mg/kg) and raddish (0.8 mg/kg), as shown in Fig. 2. Accumulation of cobalt was maximum in spinach samples from both site 1 and site 3 (92 and 130.67 mg/kg, respectively), while being maximum in coriander samples (69 mg/kg) from site 2 (Fig. 3). Among all the sites, the least concentration of cobalt was reported in bulb vegetables. Cobalt though is an essential element, but its excess is known to cause phytotoxic effects in plant and interference in uptake of other essential elements (Nagajyoti et al. 2010). Human intake of higher concentrations of cobalt cause serious toxic effects which are attributed to its affinity to sulfhydryl group or because of antagonistic effects in calcium ion channel (Simonsen et al. 2011). The concentration of copper (80.33 mg/kg) was found highest in spinach samples of site 1 which is irrigated with ground water but growing in vicinity of wastewater drain (Fig. 4). Copper is also an essential element but its higher levels are known to cause toxicity effects and acute exposure (200 mg/kg) can lead to death (FAO/WHO 2011). Arora et al. (2008) has reported the concentration of copper in spinach in range of 15.9–17.4 mg/kg. In present study, it was observed that concentration of copper in ground water irrigated site (in vicinity of wastewater drain) was many folds higher than as reported by Arora et al. (2008). Iron was most accumulated metal among all plant samples. Mean concentration of Iron in samples from site 1 was maximum in bottle gourd (624 mg/kg) followed by fenugreek (612 mg/kg). In samples from site 2 and 3 maximum iron uptake was found in fenugreek (618 and 740 mg/kg). Minimum concentration of iron was reported in garlic samples from all sites (Fig. 5). Permissible concentration of lead in fruit, tuberous and bulb vegetables is 0.1 mg/kg, while that in leafy vegetables is 0.3 mg/kg (FAO/WHO 2014). It was observed mean content of lead in 7 out of 12 vegetable samples from site 3 was higher than permissible limit. Some vegetable samples from site 1 and 2 were found to contain lead higher than permissible limit (Fig. 6). The general trend of uptake of heavy metals revealed higher concentration of metals in leafy and tuberous vegetables as compared to fruits and bulbs.Fig. 2

Bottom Line: Not just the crops irrigated with wastewater are hazardous, in present study, we have found that vegetables growing in vicinity of wastewater drain are also not safe for human consumption.Cadmium, a potential carcinogen was found in concentrations higher than permissible limits in many vegetables from all sites.Concentration of copper and lead in vegetable samples from different sites exhibited no statistically significant difference with respect to different sites.

View Article: PubMed Central - PubMed

Affiliation: Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab 143005 India.

ABSTRACT
Irrigation of agricultural land with wastewater leads to continuous buildup of metals at these sites which gets accumulated in the vegetables and crops growing on these sites. Not just the crops irrigated with wastewater are hazardous, in present study, we have found that vegetables growing in vicinity of wastewater drain are also not safe for human consumption. The risk associated with consumption of vegetables was assessed by calculating hazard quotient and results revealed that the hazard quotient for leafy and tuberous vegetables was higher than the safe limits in all the sites irrespective of mode of irrigation. Spinach was the most hazardous among all as the hazard quotient with respect to cobalt and copper was highest in spinach. Uptake trend of metals in all vegetables: Iron > Cobalt > Copper > Cadmium > Lead. Cadmium, a potential carcinogen was found in concentrations higher than permissible limits in many vegetables from all sites. Highest level of cadmium (1.20 mg/kg) and copper (81.33 mg/kg) was reported in site which was in vicinity of waste water drain but irrigated with ground water. Concentration of copper and lead in vegetable samples from different sites exhibited no statistically significant difference with respect to different sites.

No MeSH data available.