Green leafy vegetables irrigated with wastewater may contain high levels of toxic heavy metals

02/11/2018 / By Earl Garcia

A study published in the IOSR Journal of Environmental Science, Toxicology and Food Technology showed that irrigating agricultural fields and green leafy vegetables with wastewater may result in potentially hazardous buildup of heavy metals including copper (Cu), lead (Pb) and zinc (Zn), as well as nickel (Ni), chromium (Cr) and cadmium (Cd).

“On the survey of study area, it was found that continuous irrigation of agricultural land with sewage and wastewater may be possible reasons of heavy metal accumulation in the soil and vegetables. The pesticides, agrochemical and chemical fertilizers used in the agricultural field are also known to be major sources of heavy metal pollution in study areas,” the researchers said.

As part of research, a team of scientists form India’s premiere universities examined five agricultural fields in the city of Katihar in the eastern part of the state of Bihar. The researchers then collected soil samples from each field and used atomic absorption spectroscopy to analyze the presence of heavy metals in the samples. The scientists also selected five green leafy vegetables – including mustard, coriander and spinach, as well as bathua and cabbage – that were treated with wastewater. Parts of the plants such as shoots, roots and leaves were washed, air dried and crushed to detect traces of heavy metals.

The experts then assessed the people’s vegetable intake, heavy metal exposure and potential adverse effects following contaminated produce. The results revealed that both soil and vegetable samples showed heavy metal contamination that exceeded safety levels. The research team inferred that the higher heavy metal concentrations were due to higher transpiration rates from the soil to the plants, which played a central role in the growth and moisture content of the vegetables.

The experts observed that the highest transfer factor values were seen in zinc, cadmium and lead. The scientists added that vegetable samples that contained high concentrations of lead, copper and nickel were not safe for consumption.

“In many plants, Pb accumulation can exceed several hundred times the threshold of maximum level permissible for human consumption. The introduction of lead in to the food chain may affect human health. Therefore, all vegetable plant samples that were analyzed in this study were more contaminated by Pb and they were harmful for the consumers,” the researchers noted.

“The symptoms of acute oral Zn dose are tachycardia, dyspeptic nausea, vascular shock, diarrhea, vomiting, and damage of heptic parenchyma. Thus vegetables growing in soil having heavy metals contamination can accumulate high concentration of Zn to cause of serious health risk to consumers,” the experts added.

The experts stressed on the importance of routine monitoring of heavy metal concentrations in wastewater, soil and other food sources to effectively mitigate the risk of excessive heavy metal buildup in the food chain.

Smart tips to eliminate heavy metals from the body

Heavy metal accumulation from dietary sources may pose a threat to the body’s overall health and wellness. A wide array of techniques can be used to effectively rid the body of heavy metals. (Related: 10 easy ways to detox heavy metals from your body.)

Sauna and steam – Sweating it out in the dry heat of sauna or the moist heat of steam may open up the pores and remove unwanted heavy metals from the body, according to an entry posted on The Hearty Soul website.
Physical activity – Exercise may help induce sweating and flush out toxins. Likewise, working out may boost blood circulation and speed up detox.
Chelation – Health experts noted that the practice, which involves the use of an intravenous solution, may help accelerate the body’s cleansing process.
Acupuncture – The alternative treatment was touted for its many health benefits, such as increased energy and better blood circulation. The therapy’s efficacy in promoting blood circulation may expedite detoxification.
Water enemas – An article posted on The Healthy Home Economist website revealed that simple warm water enemas contain powerful healing and detoxifying effects that may benefit both the liver and the gall bladder.