Research flags heavy metal contamination in Vegetables across Bengaluru

@madhuchandan (Organic Mandya) @shameek_c (Farmizen)

This article is quite scary. Is this something you guys test with your fruits and vegetables?

Also, using wastewater for irrigation? How do farmers get access to waste water?

We actually don’t test this at Farmizen. We do random tests for pesticide residues, but not for heavy metals,.

The most common reason for this happening, is likely using sewage water for growing veggies. The select farmers that we work with are almost invariably borewell users.

We have visited farms which do use contaminated water - for example, we have seen farms use Varthur lake water, which, needless to say, is a very polluted lake. These farmers don’t get onboarded, during initial inspection. For farmers, especially fruit farmers, from other parts of the country, where we may not have been able to visit the farm for an inspection, we do ask them about their source of water, as part of our onboarding checklist.

However - I think we should start testing vegetable samples randomly for heavy metals - in addition to pesticide residues - the article is indeed scary.

Farmers living in and around waste water areas (like Kengeri) have no option but to use this waste water and it’s the same case with other districts across India.

We do residue tests to check for the contamination and from Jan 2024 we have instructed our vegetable farmers to implement water filters & softeners in their fields. AIR & WATER is polluted in INDIA!!!

It all starts with a harmless flush, a sudden gush of water that magically takes away, three otherwise wonderful resources if used each by themselves. Water, Urine & Feces.

Along with it go all the expensive and harmful chemicals we use to clean our houses. Mixes with even harmful industrial wastewater. Take a ride north of Bangalore with windows down, you will know where this water finds its way. While on one side we are reviving water bodies in the city, we are polluting our food-producing villages.

Western flush toilets without the energy-guzzling Western sewage system are a heavy burden we have half-adopted from the West and now consider a norm. Shout out to compost / eco-sans toilets. We should all use them or at least ensure the wastewater we produce is treated well.

Charcoal / Biochar can really help because of something it’s good at. Adsorption.

+Microplastics+ +Heavy Metal Contaminents+

There is one more aspect. If your farm is near a river and you use river water, and there are polluting factories upstream - that causes a problem too :frowning:

  1. It is not at all clear from the article/research (as explained by the investigator in the article) that Wastewater is indeed the source - vegetables still need to be traced. Is it really wastewater use thats caused this ? What are the other probable causes ? these are important questions to ask.
  2. Further more in our reactions to these problems we should make the difference between domestic sewage and industrial sewage - a more important implication here is we should work harder at fixing irresponsible disposal of industrial wastes - both solid and liquid.
  3. Reuse of treated domestic sewage and sludge in agriculture may be an important component of our solution to manage wastes. The liquid wastes we generate will go somewhere in the environment and if its not applied to land it is likely to get into water again (which is likely to have worse consequences) !. To refer to farmers as practicing “unethical practices like irrigation with wastewater” is in my opinion, a knee jerk response - they are equally demonstrating possibilities of circular economy. We should work on how to do so safely and how we work with all stakeholders to make this safe. Its the waste generators and the failure of actors responsible for waste management (both solid and liquid) who should be held to account. Farmers are likely responding to a water scarce context and adapting to waste-water use in agriculture. One’s own field experience around Bengaluru suggests this - and they have adapted by making different crop choices, changing fertilizer / pesticide / weedicide / fungicide application regimes, changing some farm practices for safety, introduced new processes within their realm of affordabaility and control between harvest and sending it to the markets etc.
  4. Farmers access waste-water flows from open stream flows in and around towns. These stream flows also find themselves filling up reservoirs such as the Byramangala reservoir (on the vrishbhavati) or further downstream in the arkavati reservoir. Around Bengaluru farmers are picking it up from stream flows (where stormwater flows during rainy seasons) in kaluves that flow out (eg: dakshina pinakini and vrishbhavati which may have some industrial effluent mixed - especially vrishbhavati) or they may be tapping into streamflows of wastewater streams from smaller towns around such as devanahalli, vijayapura which tend to be unpolluted by industrial waste flows.
  5. Now of course there is a formal treated waste water reuse project for recharge of groundwater done by MID which transfers 770 MLD of treated waste waters to kolar and chikkaballapur into their tanks.

We have started testing out the irrigation water on partner farms. Here’s one that we received recently. As you can see, the heavy metal levels are fine on the irrigation water, which is from borewell. So - thats good news - for one particular farm - we will be getting these done for other partner farms who supply to us regularly, as well, one by one.

Now - here’s a googly …
The home water of the farmer - cauvery water - was also tested (see the second report). The cadmium level on that is higher than the limit - this is the same water that is getting to our homes in Bangalore … will check whether this is an issue with just this sample or a systemic issue with cauvery water. Concerning.

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1 Like

Damn, do share.

Hello All,

I went through the entire thread and somehow we missed landfills as a major source of ground water contamination which also affects the lakes and water bodies around.

I remembered an article about the Mavallipura Landfill which was posted in 2018.

I have attached a link to this message which proves how landfills are a major source of ground water contamination and Bangalore is susceptible to this problem.

Polluted lakes, poor waste management contaminating Bengaluru's groundwater - Citizen Matters, Bengaluru

This could also be a reason behind the contamination in the vegetables.

I hope we can do something about this problem.


Everything here is boiling down to Citizens responsibility and their attitude towards caring his mother earth