5 Surprising Ways Ocean Pollution Affects Human Health

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Ocean pollution is killing marine life — will humans be next? The idea of eating microplastics sounds scary, but that’s what’s happening as uncontrollable seawater pollution poisons and kills fish, sea turtles and shellfish.

Marine life often mistakes tiny, floating toxic particles as food, consuming them with gusto to appease their hunger. Where do these fish end up next? It might be on your plate.

Find out how ocean contaminants affect human health and why it’s critical to minimize pollution. 

1. Microplastics Ingestion


It takes 20 to 500 years for plastics to degrade. However, they don’t disappear entirely like biodegradables. Instead, they’re broken down into tiny pieces called microplastics that pollute the ocean and its marine life. 

Foamed polystyrene claims the spotlight among types of marine litter. It comprises 10%-40% of plastic waste in waterways. Since it’s easily fragmented, the winds and waves carry it to the ocean, causing significant pollution and harm to sea life. 

Your favorite fish and shellfish may mistake those contaminants for food and eat them. Then, they may end up in your local fisherman’s boat and later on your plate as a delicious buttered shrimp or grilled salmon. The toxic chemicals from the microplastics they ingest can kill healthy cells, harm your immune system and intestinal barrier function, and promote oxidative stress. 

You don’t know if the delectable grilled fish you consumed at a local restaurant has eaten plastic, so limiting your seafood may be wise. 

2. Extended Exposure to Toxins

In addition to eating seafood, humans ingest microplastics through salt. This kitchen mineral is present in all households and is used to season dishes. People may grab a pinch or more daily to sprinkle on their steaks, pasta or salads. 

Salt comes from evaporated seawater — the same water contaminated with microplastics. One study found a wide range of these tiny particles in different salt types. 

  • 200-400 particles per kilogram in rock salts
  • 1,400-1,900 particles kilogram in refined sea salt
  • 1,900-2,300 particles per kilogram in unrefined sea salts

Researchers discovered polyethylene, polypropylene, polyethylene terephthalate, nylon and polystyrene in these salts. Because of extended exposure to these toxins, humans may ingest 0.1-5 grams of microplastics weekly, increasing the risks to their health.

Unfortunately, experts haven’t identified how much consumed microplastics can harm health. Moreover, most people are unaware they’re eating them. Reducing your salt use and increasing your plant-based options are healthier. 

3. Exacerbated Harmful Algal Blooms 

flock of birds flying above water
Photo by Lany-Jade Mondou on Pexels.com

Harmful algal blooms (HABs) occur when seaweed grows uncontrollably and produces dangerous toxins that affect marine mammals, birds, fish, shellfish and humans. 

They can produce toxins that kill fish, birds and mammals and make humans sick — or, in extreme cases — cause death. How is this related to ocean pollution? It all goes back to climate change. 

HABs are exacerbated by ocean pollution. Due to climate change, marine and freshwater environments are acidifying, warming and deoxygenating, which intensifies the blooms of harmful algae. 

Many HAB species can produce potent biotoxins that bivalve shellfish absorb. If you accidentally consume them, you may experience severe health issues and life-threatening shellfish poisoning syndrome. Some specific HAB toxins can be converted into an aerosol, causing respiratory problems in humans near or downwind of blooms. With exacerbating ocean pollution, limiting your seafood intake may be a better decision. 

4. Antibiotic-Resistant Bacteria

person with bunch medication pills on hand
Photo by Anna Shvets on Pexels.com

Another adverse impact of ocean pollution on human health is the growing number of bacteria resistant to common antibiotics. 

Researchers collected plastic samples from 18 coastal sites in Northern Ireland. It turned out that food-related marine microplastic litter or materials used for food packaging — such as milk and sandwich containers and juice bottles — contained 13 types of bacteria. 

These were 98.1% resistant to beta-lactam antibiotics — like cefpodoxime, ampicillin and ceftazidime — and 16.1% resistant to tetracycline groups like minocycline. These antibiotic-tolerant bacteria can seep into seafood that humans and animals ultimately consume. They pose serious health risks that may be untreatable with antibiotics. 

5. Nervous System Damage

Plastic may be the main contributor to water pollution. However, toxic metals, petroleum, manufactured chemicals, urban and industrial wastes, fertilizers, and pesticides also make their way to the ocean. Over 80% of waste in seawater comes from land-based sources. Exposure to these contaminants can lead to mental and physical health worries. 

Ingestion of polychlorinated biphenyls (PCBs) and methylmercury affects babies. Pregnant women who unknowingly consume seafood contaminated with these toxins increase the risk of their unborn young ones having undeveloped brains, reduced IQ and mental health problems like autism, ADHD and learning disorders. 

Meanwhile, adults exposed to methylmercury are more likely to develop dementia and cardiovascular diseases. Other manufactured chemicals from plastic wastes are capable of interrupting endocrine signaling, reducing male fertility, elevating the risk of cancer and damaging the brain. 

Minimizing Ocean Pollution Protects Human Health

There’s a direct correlation between human health and ocean pollution. Seafood is a critical food source, and what fish and shellfish consume can also end up in your stomach. Therefore, reducing the contaminants that flow into the ocean must be treated with the highest priority. These toxins are a threat to public health. 

Doing your part in minimizing plastic waste, controlling and managing it, and making eco-friendly choices are simple ways to make a difference and protect your well-being. Join the collective in preserving marine ecosystems for the good of the many.

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