Bio-accumulation & Bio-magnification

Picture Creator:Bridger


WHAT?  As said in my previous post, Bio-accumulation is the gradual accumulation of harmful substances, such as pesticides, or other chemicals in an organism.

HOW? One way is by an amount of the chemical coming into the living organism faster than the organism can break it down and use it. To put it simply, there is more input than output, therefore causing the chemical to accumulate in the organism.

The other main way is by the chemical coming into the living organism and the organism not being able to break it down or excrete it in any way whatsoever. Ergo, the chemical continues to accumulate until it eventually becomes deadly to the living organism.

Here are some examples of how this would occur: Let’s take car emissions – they are a huge contributory factor as they release chemicals into the air. Now picture these building up in trees and birds. Upon raining, these chemicals would then get washed out of the air and seep into the ground where they would certainly enter plants and the animals which eat these plants.

Another example is illustrated below and in water:

Bio accumulatiom

As humans, we sit at the top of the food chain, and those droplets of toxins in plankton/krill can be quite substantial by the time we ingest they get to us through the links in the food chain.


WHAT? Also known as bio-amplification/biological magnification, Bio-magnification is a cumulative increase in the concentrations of a persistent substance (e.g. pesticides, metals, etc.) as it moves up the food chain.

The below drawing nicely illustrates what this is, with mercury being the heavy metal


HOW? Bio-accumulation occurs at the base of a food web, usually within primary producers like phytoplankton. These microscopic organisms absorb POPs or Persistent Organic Pollutants like DDT ( an insecticide) or PCBs (flame retardants) directly from the seawater and accumulate them in their bodies over time. The toxins build up in their tissues because they are absorbed from the water at a rate faster than they can be metabolized. Bio-magnification then occurs when slightly larger organisms called zooplankton feed upon the contaminated phytoplankton and in turn absorb POPs into their own tissues at a higher concentration. The POPs can be passed from producer to consumer (to consumer, to consumer, and so on…) Bio-magnification can continue all the way up the food web or chain. Because the amounts of POPs become more and more concentrated at each link in the food chain, some of the ocean’s apex predators are at risk of gaining potentially fatal levels of POPs within their bodies, like orcas for example.


Now consider this: All the toxins we ingest through our foods bio accumulate in our bodies and as apex predators, these toxins are bio-magnified through the food chain. To top it, we live in increasingly polluted cities and use products with known and unknown chemicals on our bodies ( soaps, shampoos, moisturizers, toothpastes, perfumes, makeup etc, in our homes ( detergents, air fresheners, anti-dust sprays, sprays to polish and clean furniture etc), in our offices ( sprays to clean surfaces, floor cleaners, air fresheners etc) far from nature in concrete jungles …is it any surprise that we are increasingly sick, depressed and unhappy? 

So, I feel one should reasonably avoid as many chemicals as possible and try to simplify life by making careful, sustainable choices which work out not just for us as individuals but us as a society. And in the long run, it will work out for your pocket too!


Step 11: Lower your animal intake

Variety of farm animals in front of white background

If you are the typical person who eats animals (chicken /pork /beef /fish /lamb /goat etc. plus derivatives like ham /sausages /bacon etc)  every day of the week, then I am afraid that you will just have to buck up and cut some of that down and trust me, it ain’t as bad as you think (actually, mostly good) coz, Pinky Swear, I will show you why and how. Trust me?


For those who get an orgasm reading stats, enjoy:

The livestock sector is responsible for about 37% of human-caused methane emissions, and about 65% of human nitrous oxide emissions (mainly from manure), globally (UN FAO). These 2 gases along with water vapour and Carbon Dioxide (CO2) are naturally occurring Green House Gases (GHG). Methane though, is a more potent GHG than CO2 (by about 20-30%) which means that gram for gram, methane warms the atmosphere more than CO2. Methane also has a much shorter lifetime in the atmosphere compared to CO2 (~10 years compared to 100s of years) which will produce more rapid impacts on the global climate. This also means that any reductions in methane emissions will see a faster decrease in atmospheric concentrations when compared to CO2.

One of the main ways in which the livestock sector contributes to global warming is through deforestation caused by expansion of pasture land and arable land used to grow feed crops. Overall, animal agriculture is responsible for about 9% of human-caused carbon dioxide emissions globally (UN FAO – see previous link).

Eshel et al. 2014 estimated that “beef production demands about 1 order of magnitude more resources than alternative livestock categories”. So, if you have to, stick to poultry or pork. But let’s be honest, Eating vegetables produces lower greenhouse gas emissions. For example, potatoes, rice, and broccoli produce approximately 3–5 times lower emissions than an equivalent mass of poultry and pork (Environmental Working Group). The reason is simple – it’s more efficient to grow a crop and eat it than to grow a crop, feed it to an animal as it builds up muscle mass, then eat the animal.

For those who hate figures and numbers:

I don’t want to go into animal cruelty or their breeding and, the slaughtering practises we humans have. All these reasons are valid as far as I am concerned, even though I am myself not a vegetarian. I would like to focus however, on other things like:

Protein: Many people, especially sporty people/ gym goers/ body builders and people who want to lose weight, believe in a high protein diet- for building and, repairing of muscles after exercise and, to feel fuller for longer while ingesting less calories. Makes sense! Most people also know that meat/chicken etc are “complete proteins”, whatever that means! Let me explain: The term “complete protein” refers to the presence of “essential amino acids”. Amino acids are the building blocks of proteins. Of the 20 different amino acids, 9, known as “essential amino acids” can’t be produced by the body and we need to therefore eat them. In order to be considered complete, a protein must have all 9 of these amino acids in roughly equal amounts. So, yes, chicken, meat and eggs are complete proteins. But, humans don’t need every essential amino acid in every bite of food in every meal we eat! We only need a sufficient amount of each amino acid every day. Ergo, you don’t NEED to eat animal and animal products every day!

Also, how much protein do we need? There is a confusion about this. Here is a good read.

Hormones/ Antibiotics in food animals This is a special worry for me and the main reason I am prepared to pay over the top prices, once or twice a week, and buy organic meat/poultry. There is a raging controversy which you can read all about Here . A good reason to eat mostly vegetarian and especially if you can’t or refuse to pay organic!

Price: Let’s face it, vegetarian is wayyyyy cheaper.

Cholesterol: Bearing in mind that animal meat and derivatives can be fatty and can increase cholesterol and your risk of having heart attacks, arteriosclerosis etc. , this is another good reason to cut your animal intake.


Remember that I said that we only need a sufficient amount of each amino acid every day? So, if you have lentils with a plate of rice – voilà, that’s a complete protein meal. Pita bread and hummus? Tick. Pasta with seitan? Tick. Peanut butter with bread? Tick. So you understand more easily, a rough guide to a vegetarian complete protein meal would be: A vegetarian protein source + any carbohydrate

A vegetarian protein source could be any legume ( beans, chickpeas, lentils soybeans, peanuts) or tofu/tempeh/soya/seitan/quorn + any carb like pasta, potatoes, polenta, rice, buckwheat/quinoa etc.

The good news is that there are quite a few complete vegetarian proteins too! Here is a link, One of my favourites has to be Seitan ( next post will show you how to make it) as it is easy to make, cheap, nutritious and delicious- what a combo!