Ocean Pollution: Impacting Human Health And Our Future

Ocean pollution is a complex mixture of toxic metals, plastics, manufactured chemicals, petroleum, urban and industrial wastes, pesticides, fertilizers, pharmaceutical chemicals, agricultural runoff, and sewage. More than 80% of ocean pollution comes from land-based sources, making its way to the seas through runoff, rivers, atmospheric deposition, and direct discharges.

The ocean plays an essential role in life on Earth. It provides over 70% of the oxygen we breathe and over 97% of the world's water supply. Every day, the ocean is under attack from natural sources and manmade pollution.

The effects of ocean pollution on human health are only beginning to be understood. However, it is clear that ocean pollution poses a serious threat to human health and well-being. People are exposed to these toxins mainly by eating contaminated seafood.

- Hormonal issues

- Reproductive issues

- Damage to the nervous system and kidneys

- Cardiovascular disease

- Developmental and neurobehavioral disorders

- Metabolic disease

- Immune dysfunction

- Endocrine disruption

- Cancer

Mercury pollution: Mercury is released from coal combustion and small-scale gold mining

Mercury pollution is a significant issue that affects both the environment and human health. It is released from coal combustion and small-scale gold mining, and has a range of harmful effects.

Coal Combustion

Coal-fired power plants are a major source of mercury pollution. In the United States, coal-burning power plants emit approximately 50 tons of elemental mercury each year. Coal has higher mercury concentrations than other fossil fuels, which is why coal-fired power plants often emit larger amounts of mercury pollution. Mercury is released into the atmosphere during the combustion of coal and other fossil fuels. Once released, it contaminates the land, oceans, and streams, eventually turning into methylmercury, a harmful toxic substance that can accumulate in our food and, eventually, in us.

Methylmercury is particularly dangerous to human health. It is a neurotoxin that can cause severe central nervous system damage, resulting in sensory and motor deficits, as well as behavioural impairments. Consuming fish with high levels of mercury can lead to neurological and cardiovascular damage, endocrine disruption, an increased risk of diabetes, and compromised immune function. For pregnant women, consuming mercury-contaminated fish can cause neurocognitive problems in their children. There is no known safe level of mercury exposure below which these effects do not occur.

Small-Scale Gold Mining

Artisanal and small-scale gold mining (ASGM) is another significant source of mercury pollution. ASGM accounts for more than a third (38%) of all anthropogenic mercury emissions into the atmosphere. Mercury has long been used in ASGM to extract gold from ore, sediment, and rock deposits. The burning of mercury-gold amalgam is the primary source of mercury emissions in this process. Tens of millions of workers worldwide are engaged in the ASGM sector, producing up to 20% of the world's gold annually.

The use of mercury in ASGM has led to long-lasting toxic pollution. When miners burn mercury-gold amalgam, mercury vapour is released into the atmosphere and can end up on land or in water. Mining tailings, or solid waste, also deposit mercury onto land or water bodies. Microbes in the environment can then convert mercury into methylmercury, which can be taken up by living organisms, including fish and humans. This methylmercury accumulates in the food chain, particularly in aquatic organisms, and bioaccumulates, leading to dangerous concentrations in animals higher on the food chain.

Reducing Mercury Pollution

It is important to address and reduce mercury pollution to protect human health and the environment. The Minamata Convention on Mercury, signed by 128 countries, regulates the use of mercury in ASGM. Additionally, the United States Environmental Protection Agency (EPA) has implemented standards and regulations to reduce mercury emissions from coal-fired power plants. These efforts are crucial to minimize the harmful impacts of mercury pollution on both the environment and human well-being.

Plastic waste: Plastic waste kills marine life and is consumed by humans in the form of toxic microscopic particles

Plastic waste is a significant contributor to ocean pollution, with plastic accounting for as much as 80% of marine pollution. It is estimated that up to 13 million metric tons of plastic end up in the ocean each year, and it is predicted that by 2050, the weight of ocean plastics will exceed the combined weight of all the fish in the seas. This plastic waste is having a devastating impact on marine life and is also being consumed by humans in the form of toxic microscopic particles, with potentially harmful consequences for human health.

Plastic waste kills marine life through entanglement, injury, ingestion, and toxic contamination. Large plastic items such as fishing gear, six-pack rings, and plastic bottles can entangle marine mammals and fish, leading to starvation, injury, and increased vulnerability to predators. Discarded fishing nets can also smother and damage coral reefs. Smaller plastic fragments can be mistaken for food by seabirds and other marine species, leading to suffocation and starvation. It is estimated that plastic contributes to the death of more than 100,000 marine mammals every year, including up to a million seabirds.

One of the most concerning aspects of plastic pollution is the presence of microplastics, tiny plastic particles that result from the breakdown of larger plastic items. These microplastics are easily ingested by marine life, including fish and shellfish, and can accumulate in their tissues. As these particles are invisible to the naked eye, they are often consumed unknowingly by wildlife. Microplastics can absorb toxins from the surrounding marine environment, including pesticides and heavy metals, and these toxins can then be transferred to the fatty tissues of the organisms that ingest them. This process, known as bioaccumulation, can result in toxic contamination of marine life.

Humans are also consuming microplastics, both directly from the environment and indirectly through the consumption of contaminated seafood. Microplastics have been found in various sources of food and water, including salt, beer, fresh fruit and vegetables, and drinking water. They are also present in the air we breathe, as plastic fibres can become airborne and be inhaled. It is estimated that humans may be consuming tens of thousands of microplastic particles each year, with the exact number depending on factors such as diet and water consumption habits.

The health impacts of consuming microplastics are still not fully understood, as this is a relatively new area of research. However, there is growing concern among scientists that the accumulation of plastic in the human body could have toxic effects. Some types of plastic are made with toxic chemicals, and even those that are not can pick up trace amounts of toxins from the environment. These toxins may impact the immune system and upset the balance of gut bacteria. In addition, the complex combination of chemicals used to make plastics, including additives, can be toxic, and the long-term effects of exposure to these chemicals are not yet known.

While the full extent of the harm caused by microplastics is still uncertain, the presence of plastic waste in the ocean is undeniable, and the potential risks to human health are cause for concern. It is essential that we take action to reduce plastic pollution and minimize our exposure to these toxic microscopic particles.

Harmful algal blooms: Pollution along the coasts increases the frequency of harmful algal blooms, which produce toxins associated with dementia, amnesia, neurological damage, and rapid death

Ocean pollution is a pressing issue that poses a direct threat to human health and well-being. Harmful algal blooms (HABs) are a significant consequence of this pollution, particularly along the coasts, and they have severe impacts on both aquatic ecosystems and human populations. These algal blooms produce neurotoxins that have been linked to various adverse effects on humans, including dementia, amnesia, neurological damage, and even rapid death.

HABs are the result of an overgrowth of certain types of algae, specifically cyanobacteria, dinoflagellates, and diatoms, which are stimulated by excess nutrients in the water. These nutrients, such as nitrogen and phosphorus, find their way into coastal waters through runoff from agricultural activities, sewage, and industrial waste. The presence of these excess nutrients allows the algae to grow rapidly and out of control, forming thick mats or scum on the water's surface, and sometimes even underneath, making it hard to detect.

The toxins produced by HABs have severe effects on both human and animal health. In humans, the primary target of these toxins is the neurological system, leading to a range of neurobehavioral abnormalities. The toxins are typically contracted through the consumption of contaminated seafood, including fish and shellfish. Amnesic Shellfish Poisoning, Ciguatera Fish Poisoning, and Possible Estuarine Associated Syndrome are some of the most frequent HAB-related illnesses associated with neuropsychological disturbances.

The impacts of these toxins on human health can be severe and even life-threatening. In addition to the risk of death, exposure to HAB toxins has been linked to neurological problems similar to those seen in neurodegenerative diseases such as Alzheimer's and ALS. For example, a study on vervets found that exposure to the neurotoxin BMAA, produced by cyanobacteria in algal blooms, resulted in the development of neurofibrillary tangles and amyloid plaque deposits in the brain, which are also commonly found in patients with Alzheimer's Disease.

The frequency and severity of harmful algal blooms are expected to increase due to climate change and warming sea waters, making it crucial to address this issue urgently. Implementing measures to reduce coastal pollution, such as controlling industrial waste, agricultural runoff, and sewage, is essential to mitigate the impacts of HABs on human health and the environment.

Oil spills and chemical wastes: Oil spills and chemical wastes threaten the microorganisms in the seas that provide much of the world's oxygen supply

Oil spills and chemical wastes threaten the microorganisms in the seas that provide much of the world's oxygen supply. Oil spills and chemical wastes can have a devastating effect on marine life, including microorganisms.

Oil spills can destroy the insulating ability of fur-bearing mammals, such as sea otters, and the water repellency of a bird's feathers, exposing these creatures to harsh elements. Without the ability to repel water and insulate from cold water, birds and mammals will die from hypothermia. Oil spills can also affect the lungs, immune function, and reproduction of dolphins and whales.

Chemical wastes, such as mercury, can also have a detrimental effect on marine life, including microorganisms. Mercury is released from coal combustion and small-scale gold mining. Mercury can cause developmental defects, cardiovascular disease, and dementia in humans.

The combination of oil spills and chemical wastes can have a devastating effect on the health of marine life and humans, and it is important to address this issue to protect the health and well-being of both.

Noise pollution: Noise pollution can interfere with marine life and human communication and can cause hearing loss

Noise pollution is excessively loud or frequent noise, such as that from traffic, airplanes, or construction. It can have a range of negative effects on both physical and mental health.

Noise pollution can cause hearing loss in humans. At certain levels and durations of exposure, noise can cause physical damage to the eardrum and the sensitive hair cells of the inner ear, resulting in temporary or permanent hearing loss. Hearing loss does not usually occur at SPLs below 80 dBA, but most people repeatedly exposed to more than 105 dBA will experience some degree of permanent hearing loss.

Noise pollution can also cause a range of other health issues in humans, including increased blood pressure and pulse rate, irritability, anxiety, mental fatigue, and interference with sleep, recreation, and personal communication. Children living in areas with high levels of noise pollution may suffer from stress, as well as impairments in memory and attention span.

Marine animals, such as whales, dolphins, and porpoises, are highly dependent on underwater sound for their survival. They rely on sound to communicate, locate mates and prey, avoid predators, navigate, and defend their territories. Noise pollution can interfere with these key life functions, causing behavioural and physiological changes, masking their ability to detect sound, and even leading to injury and death.

Underwater noise can cause marine mammals to panic and ascend too quickly, resulting in decompression sickness and tissue damage from gas bubble lesions. Loud noises can also cause immediate hearing loss, which can prove fatal for marine mammals that rely on sound for survival. Noise pollution has been linked to mass stranding events of whales and dolphins, with the number of recorded strandings likely representing only a small percentage of the actual number of incidents.

Noise pollution from ships, seismic surveys, explosions, construction, and sonar devices has turned the once peaceful ocean environment into a loud and chaotic space, threatening the natural soundscape and causing significant harm to marine wildlife.

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