Beware of toxic vegetables
From Sarbjit Singh
Tribune News Service

CHANDIGARH, Sept 28 — Beware of the vegetables you eat. These may be toxic. Experts in Punjab Agriculture University engaged in indexing of nutrients in various foodgrains and vegetables have stumbled on toxic elements in certain vegetables while analysing these in the laboratories.

The upper layer of the soil fed by sewerage water containing industrial affluents have turned toxic, especially near major industrial towns and cities likes Ludhiana, Amritsar, Mandi Gobindgarh, Malerkotla and Jalandhar.

Vegetables grown in such soil have been found contaminated with toxic elements. In the course of analysis, the toxic elements detected in the edible parts of certain vegetables were chromium, arsenic and nickel. These are heavy metals and some of these like arsenic, described as a violent poison, are dangerous for human health beyond a permissible limit.

Information collected by TNS has revealed that mainly potatoes, tomatoes, cauliflower, peas and leaf vegetables like methi, mustard, mentha (pudina) have been found contaminated by toxic substance. The extractable contents of these vegetables were analysed in the labs of the PAU. Interestingly potatoes, cauliflower, mustard (sarson da sag) and peas are the most eaten vegetables in this part of the country.

Confirming the presence of toxic elements in certain vegetables, Dr C.L. Arora, Senior Chemist, in the Department of Soils, PAU, told TNS that the edible parts of the different vegetables and corresponding soils were analysed for cadmium (Cd), mercury (Hg), nickel (Ni), arsenic (As) and chromium (Cr). The status of mercury (0.65-1.39 ppm)was higher than the permissible limit of 0.02 ppm of fresh weight.

Potato, in general, and certain select samples of mustard, methi, mentha also had a higher concentration of lead. The leaf samples of methi and mentha also recorded a higher amounts of nickel, arsenic and chromium, he added.

The extractable contents of arsenic, chromium, nickel and lead were found to be much higher in the fine textured sewage-irrigated soil than the light texture sewage-irrigated soil. The sewage-irrigated soil under cauliflower had much higher concentration of extractable lead and Nickel (5.1 and 1.3 ppm, respectively,) in comparison to the tubewell-irrigated soil. The curds (flowery part) of cauliflower had a higher tendency to accumulate nickel and lead than leaves.

Dr V.K. Nayyar, another Senior Soil Chemist of the Department of Soils in PAU, Ludhiana, says examination of the samples of polluted soil in the state has revealed high level of toxic substances in the upper layer.

For instance cadmium was found above 1.70 ppm in the upper surface up to 15 cm of soil in polluted land while in the surface below 15 cm to 30 cm it was above 1.50 ppm. In non-polluted land it was less. The presence of cadmium in upper surface of soil has been found quite high in polluted land near Mandi Gobindgarh, Ludhiana, Jalandhar and Amritsar.

Even toxicity has started reflecting in certain foodgrains. But its level is not alarming, according to experts. However, if this trend continues in vegetables then days are not far when it would touch alarming and even dangerous level in foodgrains.

Dr Arora says vegetable growers should not use sewerage water containing industrial affluents. This is the only way of saving vegetables turning toxic. Otherwise consequences could become very bad.