Home > Food & Water > Fish and Heavy Metal Contamination

Fish and Heavy Metal Contamination

By: Helena Stratford - Updated: 6 Oct 2016 | comments*Discuss
 
Fish Metal Mercury Contamination Health

The heavy metal contamination of fish does not mean that the oceans are buzzing with the sound of salmon and tuna, head banging to AC/DC – although that would be a rather nice image!

Rather, it is the more serious issue of our marine life being poisoned by toxic levels of metals, which are then passed up the food chain.

What Are Heavy Metals?

Heavy metals such as zinc, iron, and copper are naturally occurring substances in the Earth’s crust. Some are needed by humans in trace amounts to maintain optimum body function, whilst others such as mercury, arsenic, and cadmium can be harmful. All metals can be toxic if levels are too high.

Why do Heavy Metals Contaminate Fish?

Marine animals such as fish are able to readily absorb metals and their bodies regulate to accommodate their presence. They are easily stored in fatty tissue and will bio-accumulate if the fish is exposed to further contamination.

Copper And Zinc

It has been found that the presence of copper in water affects the populations of fish even in very low doses. Metals such as copper and zinc can leach into water from the mining industry, via storm drains and from agricultural run-off from fields.

Although levels of these metals are monitored in water, at such low levels as 2 parts per billion they are considered almost too insignificant to worry about. However recent research has discovered that even at extremely low levels copper will disrupt the sense of smell of fish preventing them from detecting predators or recognising their eggs.

High levels of copper in humans can cause diarrhoea, stomach cramps, and vomiting.

Mercury

There is currently triple the amount of mercury falling from the sky than at the time of the Industrial Revolution. It is also contaminating many areas as a result of unregulated gold mining.

The metal is absorbed by fish and other aquatic animals, and passed up the food chain to any other fish-eating species.

Scientists today are concerned that people who eat fish contaminated with mercury will be put at risk – particularly pregnant mothers and children as mercury poisoning has been shown to adversely affect brain development. However it is also being linked to a higher risk of heart disease and stoke in men as well as memory loss, and central nervous system damage.

Cadmium

Cadmium is a heavy metal which has been found in quite high quantities in larger fish like tuna and swordfish. This is because the metal accumulates over time and also because these fish are higher up in the food chain and so will be eating already contaminated prey.

Cadmium is very toxic to humans and has been linked to kidney disease, lung problems, and prostate cancer.

Should You Eat Fish?

Whilst it would be wise to watch the amount of fish you consume – especially if pregnant, there is also evidence from British scientists to support the theory that the health benefits of the beneficial nutrients from fish such as Omega 3 outweigh the negative effects of heavy metal contamination.

You might also like...
Share Your Story, Join the Discussion or Seek Advice..
When ordering fish for a restaurant, is there any area that would be questionable?
???? - 27-May-14 @ 7:10 PM
what are the limits of heavy metals in fishery products like arsenic, berllylium, nickel, chromium, cynides.
trevor - 16-Jun-11 @ 12:32 PM
Share Your Story, Join the Discussion or Seek Advice...
Title:
(never shown)
Firstname:
(never shown)
Surname:
(never shown)
Email:
(never shown)
Nickname:
(shown)
Comment:
Validate:
Enter word:
Topics
Latest Comments
  • Bridget
    Re: Pollution: Understanding Food Labels
    Hi. I'm trying to find out more about 1. Food labelling for air freighted foods and 2. Legislation to tax or reduce…
    20 April 2019
  • Piggy
    Re: Stop Smoking
    There seems to be a strong smell of weed coming from the house two doors down it’s been smelling for a few months now it’s and it’s all day and night…
    1 April 2019
  • Mr D
    Re: Complaining About Smell Pollution
    We stay in a flat in Silverton. There is a Mr Daantjie whose flat is stinking so much, that you can hardly breath upon…
    1 April 2019
  • Satya
    Re: Complaining About Smell Pollution
    Excellent and thanks for your guidence Hope that I will be receiving such good materials from your end.
    31 March 2019
  • Mick
    Re: Bad Smells and the Law
    Our garden is next to a cesspit that serves 16 houses, this is controlled by the local housing association, the cesspit is not covered and…
    27 March 2019
  • Miela
    Re: Complaining About Smell Pollution
    My neighbour has 2 dogs infront close wth a plank no space to run jst bark whl day and the smell off dog poo stinks so bad i…
    26 March 2019
  • Baddabing
    Re: Complaining About Smell Pollution
    Neighbors have a bad smell coming from there yard. It's been that way for a few weeks now.. I know they have alot of dogs as…
    17 March 2019
  • Tiego
    Re: Complaining About Smell Pollution
    Our is doing pig farming in a township. The smell is bad when it is hot is unbearable... We are forced to keep the door…
    12 January 2019
  • Jennie
    Re: Complaining About Smell Pollution
    I live in a house with a neighbour who is filthy dirty. Keeps being sick in his room and Letton the smell go though the…
    26 December 2018
  • Rian
    Re: Complaining About Smell Pollution
    My neighbors house house stinks of stale old food. Stale rice and tomatoes and the smell is potent! Is horrible and strong…
    22 December 2018