Mercury, PCB, Microplastics and PFAS... is it safe to eat Fish?

I love fish. Its my favorite type pf protein so everytime I dig into this topic it truly pains me.

UP until a few years ago the main concern with fish was to avoid mercury. Doctors would tell pregnant women to avoid high mercury, fish and that was it.

Today, however, Our oceans, rivers and lakes are so polluted that, fish can be a source of harmful chemicals including PCB, microplastics, mercury and PFAS

Fish do have some health benefits of course ( for example, wild salmon and sardines can be an excellent source of omega-3 fatty acids, which contain ALA, EPA and DHA) so the question remains: is it safe to eat any type of fosh? And if so which?

First lets look into the most common chemicals found in fish today

Methylmercury

A well studied neurotoxin that is known to also harm the kidneys and nervous system
Pregnant women, women thinking of becoming pregnant and young children should avoid fish with high mercury levels as even small amounts of mercury can interfere with brain development,
Eating contaminated fish is the number one cause of mercury exposure in America.

Found in nearly all fish and shellfish at traces levels, however, since small fish are eaten by larger fish up the food chain, concentrations of methyl mercury are higher in large, predatory deep-ocean fish.

TIPS TO LOWER EXPOSURE TO METHYLMERCURY VIA FISH

Large fish (swordfish, shark, king mackerel and tilefish) have the highest levels of methylmercury and should be avoid by vulnerable populations and rarely consumed by everyone else.
Fish low in mercury include:

Shrimp, salmon, pollock, and catfish, Anchovies Butterfish Catfish, Clam, Crab (Domestic) Crawfish/Crayfish Croaker (Atlantic) Flounder* Haddock (Atlantic)* Hake Sole (Pacific) Squid (Calamari)

SAFE TO EAT?

I recommend avoiding all high mercury fish during all stages of pregnancy and ideally early childhood. Limit to 2 times a month during later childhood/ teen years. Eat at your own discretion as an adult (I am looking at you sushi lovers)

2. Microplastic

An emerging contaminant- microplastic levels have been found in some fish - the direct result of plastic pollution in our oceans-
According to a 2017 UN report, there are more than 51 trillion microplastic particles in the sea, more than 500 times the number of stars in the Milky Way.
we can expect levels in fish to continue to increase as plastic pollution increases
It is not known if eating fish with high micro plastic levels harms humans. This is still being studied, but we have seen that chemicals used in the manufacture of plastics can leach out and become ingested by marine life.
Plastic pollution was found to interfere with the growth, photosynthesis and oxygen production of the most abundant photosynthetic bacteria group in the ocean.
Additionally, fish exposed to microplastics reproduce less but their offspring who weren’t directly exposed to plastic particles, also had fewer young, suggesting the effects can linger into subsequent generations.

TIPS TO DECREASE MICROPLASTIC INGESTION VIA FISH

Currently fish with highest levels of micro plastics are: mollusks (such as clams, mussels, oysters and scallops) and shellfish
Moderation is key: Reduce all fish consumption to 1 or 2 a week

3. PCBs

Are chemicals that were made for a long list of industrial uses (lubricants, fire retardants, plastics and more) from 1929 until they were banned in 1979
PCBs are not highly toxic with a single dose (as in a single meal), but continued low levels of exposure (for example, eating contaminated fish over an extended period of time) may be harmful.
PCBs tend to act as endocrine disrupting compounds, Studies of PCBs in humans have found increased rates of melanomas, liver cancer, gall bladder cancer, biliary tract cancer, gastrointestinal tract cancer, and brain cancer, and may be linked to breast cancer. EPA rates PCBs as "probable human carcinogens,"
When fishing look for local advisories on PCB levels in local waters.

TIPS to reduce exposure to PCBs in fish

Trim away fatty areas (belly, top back and dark meat along the side)
Remove skin before cooking to allow fat to drain off
Grill, bake or broil fish and allow fat to drain off
Do not fry or deep-fry fish because frying seals in any chemical pollutants in the fish's fat

For Salmon (recomendations made by Physicians for Social Responsibility and the Association of Reproductive Health Professionals):

choose wild salmon when possible
Canned Pacific salmon can be eaten max twice a week
Fresh or frozen wild Pacific salmon can be eaten up to twice a month
Fresh or frozen farmed Atlantic salmon can be eaten once every two months

4. PFAS

PFAS chemicals are a family of over 9,000 chemicals widely used for their ability to be stain/ water/ grease resistant.
Among the health concerns linked to PFAS. ARE: decreased immune response, an increased risk of thyroid disease and of reproductive and developmental harms and links to cancer
PFAS CHEMICALS bioaccumulate and can take Decades to break down
I believe that there are no safe levels of PFAS, however it is virtually impossible to avoid them so the key thing is to focus on reducing exposure
One of the biggest challenges to understand PFAS contamination and develop a true risk assessment is that testing isnt great. There are thousands of PFAS chemicals that we just dont know how to Test for and many we just dont even know exist

PFAS in FRESHWATER FISH

(In the US- but studies around the world have found this is a big problem at a worldwide level )

With no federal guidance, what is considered safe to eat varies significantly among states, and most ( including California) provide no regulation.

According to the Environmental Working Group , a single serving of freshwater fish can be the equivalent of drinking water contaminated with high levels of PFAS for a month. Levels are so high that for anyone consuming freshwater fish, even infrequently, it would likely be their major source of exposure over the course of the year.

Locally, some authorities know and warn about these issues. For example, In Alaska, several lakes are designated catch and release only because of PFAS contamination from firefighting foam. A study by the U.S. Geological Survey and Pennsylvania Department of Environmental Protection released in August led to a warning to avoid eating fish from the Neshaminy Creek watershed. But many states do not warn their citizens about this danger.

Sadly, National EPA tests show nearly all fish in U.S. rivers and streams are contaminated with PFAS

Ironically PFOS, the type of PFAS chemical most commonly found in fish jn both the US and UK is no longer made in the U.S nor UK. But, due. To its persistence in the environment has accumulated and is making its way back to us via the food cycle

Do ocean fish contain PFAS?

Kind of- but its not as bad as freshwater… it seems. Different studies of market fish ( fish bought in supermarkets) have found different things - some do find PFAS in fish while others dont. It is just not consistent. So, the truth is we dont know how extensive the problem is.

A study that looked at PFAS in the Miami area explains it well. When they began tracking the sources of PFAS in Biscayne Bay, they found hot spots of these chemicals around the exits of urban canals – especially the Miami River, Little River and Biscayne Canal. Each of these canals, we found, is a major point source contributing to the presence of PFAS in offshore areas of the Atlantic Ocean

They then made a model to predict how ocean currents would disperse PFAS coming out of those canals and into coastal areas. Conclusion: PFAS concentrations are highest close to the canals, decreased along the bay and declined as ocean water became deeper and more saline, which makes PFAS less soluble in water.

Overall, PFAS concentrations are almost six times higher in surface waters near land compared with deep-water samples collected 13 to 33 feet (4 to 10 meters) below the surface in the bay and offshore. That suggests the highest risk is to pelagic fish that hang out in surface waters, such as mackerel, tunas and mahi-mahi.
Additionally that 2020 study found Sardines, anchovies, and soles presented the highest PFAS levels.

The presence of PFAS in coastal Waters are not limited to Florida- this is likely A worldwide problem ( but likely worse in more industrialized locations)

CAN YOU REDUCE PFAS IN FISH?

PFAS in fish, as even exceedingly low levels are now believed to threaten human health.
In my opinion freshwater fish should not be eaten by anyone, especially pregnant women and children.
If you want to have an occasional fish fillet due to taste or other benefits ( omega’s in salmon for example) your safest bet is likely to space this out- perhaps Just once a month or every few months and choose fish caught in the deep ocean.
According to FDA RESEARCH, store,-bought fish caught in the ocean, like imported wild Atlantic salmon and canned chunk tuna, appear to have lower PFAS levels,

Bottom line?

It is tragic what we have done to our waterways and oceans. These contaminants that are now in almost all fish are now coming back to affect our own health. Sadly, these contaminants are not only found in fish as all, except perhaps mercury, can also be found to different extents in many foods we eat. Our focus should be to continue to REDUCE our exposure (in this case by eating a balanced organic healthy diet) and try to focus on our own natural detoxifying capabilities to be able to deal with the toxins we do encounter on a daily basis

In terms of fish, some healthier guidelines include:

As with everything in life: moderation is key. Choose the healthiest fish and limit it to 1 or 2 meals a month
Some fish should probably be avoided- especially during windows of susceptibility like pregnancy and childhood
Herring, filled with omega-3s, has minimal mercury and has consistently tested not detected or very very low levels PFAS

sources:

What to do about mercury in fish

https://www.health.harvard.edu/staying-healthy/what-to-do-about-mercury-in-fish

https://www.nrdc.org/stories/mercury-guide

“ Microplastics in Seafood and the Implications for Human Health“ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6132564/

NRDC mercury Guide

https://www.sciencedirect.com/science/article/pii/S0048969719346169

Transgenerational effects and recovery of microplastics exposure in model populations of the freshwater cladoceran Daphnia magna Straus

https://www.sciencedirect.com/science/article/pii/S0048969718308088

http://seafood.edf.org/common-questions-about-contaminants-seafood

https://theconversation.com/pfas-forever-chemicals-are-getting-into-ocean-ecosystems-where-dolphins-fish-and-manatees-dine-we-traced-their-origins-216254#:~:text=Because%20PFAS%20can%20enter%20the,ecological%20and%20human%20health%20implications.&text=In%20a%20new%20study%2C%20we,ways%20to%20reduce%20the%20harm.

https://www.nationalacademies.org/our-work/guidance-on-pfas-testing-and-health-outcomes