We generally think of pesticides as entering our body through the food we eat, for example, incomplete washing of an apple. So we may wonder how we could possibly be exposed to pesticides through salmon. It's simple: many pesticides stay in body tissues, so if it's in the salmon, it's in us. Pesticides can enter the salmon via numerous different pathways, from residues and direct additions in the feed to traces in the water. 



On 9 June 2021, Huon Aquaculture’s head veterinarian, a fellow named Dr Steve Percival, wrote in an opinion piece in the Hobart Mercury that, “With regards [sic] to salmon, ethoxyquin is only used in certain feed ingredients like fish meal. It is not added separately to feed. Even if a person was to eat 4kg of salmon every day, they would still be below the acceptable level advised by the World Health Organisation. During testing of our salmon products, no residues of ethoxyquin have been detected” [1]. While his poor grammar can certainly be forgiven, what cannot be so easily dismissed is his failing to be clear that his company’s most recent flesh-testing results did not find ethoxyquin because they did not test for it [2]. It feels duplicitous to say it wasn’t found, when in fact in the testing they have provided, it wasn’t looked for. 

It also seems a curious argument to say that it is not added separately to feed. The point is not when in the feed cycle it is used, but rather, that a potentially dangerous pesticide is indeed in the feed. In general, ethoxyquin is not permitted in food intended for human consumption [3]. Regardless of what point it enters our food source, if a pesticide is in the feed, then the pesticide is in the fish, and therefore the pesticide gets into people who eat these contaminated fish. 

Ethoxyquin is a chemical used by the salmon industry as a feed additive to prevent spoilage and spontaneous combustion of fishmeal during shipping. It was originally invented by Monsanto to stop rubber from cracking, prior to being co-opted by the pear industry to prevent scald. 

This chemical is not as innocent as it might seem. One study found that the mandatory 14 day depuration -- or purifying -- period prior to slaughter was not sufficient for complete elimination of ethoxyquin residues [4]. Another study found that it impaired immunity in tilapia [5]. Yet another found that it suppressed growth [6], while still another found that fish larvae and aquatic crustaceans displayed abnormalities including body deformities, missing eyes, reduced heart rate, and yolk sac swelling [7]. 

The safety of ethoxyquin is controversial. According to a study by the European Food Safety Authority (EFSA), "Ethoxyquin quinone imine shows structural alerts for mutagenicity, carcinogenicity and DNA binding; no conclusion on the absence of genotoxicity of ethoxyquin quinone imine is possible. p-Phenetidine is a recognised possible mutagen" [8]. Or in plain English, the EFSA was unable to conclude that ethoxyquin is safe in animal feed because the break-down product of ethoxyquin called Ethoxyquin quinone imine may cause mutations and cancer, and may damage DNA, while p-Phenetidine, an impurity associated with ethoxyquin, is recognised as possibly causing mutations. 

Here’s our take on it: while cancer isn’t the only game in town that we may be concerned about, there is a jarring mismatch between what we are told is a healthy food, and the reality that it has controversial chemicals that some of us may not want in our body. While the cancer question remains outstanding, the 'nothing to see here' veneer may be toxic to our sense of trust. 

Too often, we suffer the consequences of the slow pace at which action to protect us from dangerous chemicals lags behind knowledge of their detrimental effects. If there was ever a reason to employ the Precautionary Principle, certainly food safety would have to be it. 



We have been informed of independent testing on salmon fillets from supermarkets that had worrisome levels of glyphosate. We are trying to get ahold of these test results. 

Glyphosate, or more commonly known by its trade name, Roundup, is the world's most produced herbicide and is used extensively in agriculture and garden products. Glyphosate has been positively associated with non-Hodgkin lymphoma in numerous studies [9]; however, other studies were inconclusive [10]. Analysis by the World Health Organization (WHO) led that agency to classify glyphosate as "probably carcinogenic in humans" (category 2A) based on limited evidence in humans but sufficient evidence of tumours in animals [11]. However, not all organisations are equally assertive. 

Concerns about glyphosate and cancer have been the subject of numerous very high profile legal settlements. For example, awards in the first three claims to see court did not go well for Monsanto, the maker of glyphosate: $289 million in August 2018 [12], $80 million in March 2019 [13], and $2 billion in May 2019 [14], though all were reduced on appeal. By April 2019, more than 13,000 cases were pending, and by July 2019, this figure swelled to more than 18,000 [15]. Perhaps not surprisingly, Bayer, the new owner of glyphosate, settled all cases collectively for $10 billion in 2020 [16]. 

Watch this space as we learn more about the putative residues of glyphosate in salmon, and what that means for people who consume it. 


Other Pesticides

A variety of other pesticides are undoubtedly used in the production of soy and chickens in salmon feed, and also may enter our waterways as runoff from agricultural operations. The extent to which these have the capacity to find their way into salmon, we do not yet know. We are investigating these, so check back with this page from time to time. 


Should We Worry?

Besides cancer implications, which are scary enough, pesticides pack a neuro-antagonistic payload. The problem is simple: pesticides are developed to damage the nervous system of animals. So, why on earth do we act so surprised when they do? And given that they do, why don’t we have a better system for keeping them out of our food? 

In nature, in our food, and in our body, pesticides may have unpredictable outcomes like spontaneous transformations, chemical interactions, or synergystic effects. This is particularly worrisome because many pesticides store in fats, and at a hefty 18% fat, farmed salmon has the capacity to mainline toxic substances straight into our body. 

For example, in the uncontrolled natural laboratory of water, air, and sunlight, wholly new combinations can spontaneously transform seemingly innocuous substances into toxic ones. 

We have no control whatsoever over what occurs in these instances: roadside puddles, babbling brooks, and peaceful reservoirs can become cauldrons of hell when different chemicals applied by different people for different purposes come into contact. New chemicals may be difficult to detect. Because we haven’t yet developed tests for them, we only become aware of their presence when we notice large numbers of dead fish or birds, or local cancer clusters. 

Another menacing aspect of pesticides is chemical interaction. Doctors and pharmacists take great care to ensure that we don’t accidentally take medicines in combinations that may harm us, yet our fruit salads and mixed greens bring us into contact with combinations that were never meant to pair up. The sorts of neurotoxic and cytotoxic chemicals that are used industrially to turn on and off different biological processes can have debilitating or lethal effects in synergistic combination. 

And because many contaminants accumulate in our bodies over time, the problem doesn’t even have to be the salad we eat for lunch today. Trace chemicals stored in our tissues a month ago may interact with something we ate last week, pushing us over some unperceived threshold. We are rarely aware of the moment a threshold is crossed – except for the cases where we become violently ill and perhaps die. More likely, these chemical changes slowly cause cells in our body to work differently or become malignant. 

The biggest problem with all these toxic substances isn’t the acute deaths – although those are alarming and unwelcome – but their now-ubiquitous accumulation in our water supply, our soils, our corn and apples and salmon – and in us. It’s a silent, steady, sinister build-up of toxicants as our bodies march toward malignancy. In all of us, seven billion and counting. 

Exposure to pesticides has been linked with a whole host of nasty health impacts, including... 

  • Alzheimer’s disease [17] 
  • A 70% greater risk of Parkinson’s disease [18] 
  • Diabetes [19] 
  • Menstrual abnormalities [20] 
  • Male infertility [21] 
  • Prenatal brain damage and Asperger’s Syndrome-like characteristics [22] 
  • Birth defects [23] 
  • Lower IQ and ADHD in children [24] 
  • Inherited obesity [25] 
  • Breast cancer [26] 
  • High rates of lymphoma and leukemia in farming communities [27, 28] 
  • A veritable blizzard of other cancers [29, 30] 



[Click here to go to Pesticides References]

Image Pesticides by andypowe11 CC BY 2.0 Flickr