Marine Pollution: Impacting Human Health And Wellbeing

Marine pollution has far-reaching consequences for human health and well-being. Over 80% of marine pollution comes from land-based sources, and the chemical and plastic pollutants that contaminate our oceans and seas are now found everywhere from the Arctic to the deepest depths. The impacts of marine pollution are felt most by those in small island nations, indigenous communities, coastal communities in the Global South, and fishing communities worldwide.

Consumption of contaminated seafood

Marine pollution poses a serious threat to human health, with toxins from the ocean entering the human body primarily through the consumption of contaminated seafood. One of the most common and dangerous toxins found in seafood is mercury, which can cause severe damage to the brain and nervous system, especially in unborn babies, infants, and children. Mercury enters the oceans primarily through coal combustion, with coal being the major source of mercury pollution. When coal is burned, mercury is released into the atmosphere and eventually makes its way into the sea. It is then consumed by fish, accumulating in larger predatory species such as bass, tuna, swordfish, and some sharks. Humans who eat these contaminated fish are at risk of ingesting high levels of mercury, which can lead to neurological disorders, developmental issues, and cardiovascular problems.

Another concern is the presence of plastic waste in the oceans, which accounts for an estimated 80% of marine pollution. Plastic breaks down into microplastics, which are then ingested by fish and shellfish. These microplastics absorb harmful chemicals, such as pesticides and toxic metals, and are passed on to humans when they consume seafood. While the exact risks of microplastics to human health are still being studied, they have the potential to cause significant harm.

In addition to mercury and plastic, other manufactured chemicals and pollutants also contaminate seafood. These include polychlorinated biphenyls (PCBs), dioxins, pesticides, and industrial chemicals. These toxins have been linked to various health issues, including cardiovascular disease, developmental and neurobehavioral disorders, metabolic disease, immune dysfunction, endocrine disruption, and cancers. The complex mixture of toxins in the ocean poses a significant risk to human health, and it is important for consumers to be aware of the potential dangers associated with consuming contaminated seafood.

Climate change and global warming

One of the primary drivers of climate change is the increase in greenhouse gas emissions from burning fossil fuels. This leads to a rise in global temperatures, and the oceans absorb a significant portion of this excess heat. As a result, ocean warming is occurring, contributing to sea-level rise and altering marine ecosystems. Warmer waters can change the metabolic rates of marine organisms and trigger shifts in their distribution, leading to potential food shortages for humans who depend on these fisheries.

Climate change also contributes to ocean acidification, as the oceans absorb more carbon dioxide from the atmosphere. This change in pH makes it more difficult for some organisms, such as corals, molluscs, and plankton, to build and maintain their structural integrity. Ocean acidification can also increase the toxicity of certain heavy metals and chemicals, further endangering marine life.

In addition, global warming and climate change lead to deoxygenation, or the loss of oxygen in seawater. Warmer waters have a reduced capacity to hold dissolved oxygen, and this, coupled with increased oxygen consumption by organisms and changing ocean circulation patterns, can create hypoxic or anoxic conditions that are lethal to many marine species. These changes in oxygen levels can have far-reaching consequences for marine food webs and human fisheries.

The combination of ocean warming, acidification, and deoxygenation forms what is known as climate change's "deadly trio," which poses a significant threat to marine biodiversity and ecosystem resilience. These factors act synergistically, damaging marine life and ecosystem structure and functions. The effects can be direct, such as creating lethal conditions due to high temperatures, or indirect, such as exacerbating the impacts of other drivers of change.

To address these issues, urgent action is needed to reduce greenhouse gas emissions and mitigate the impacts of climate change on marine environments. This includes transitioning from fossil fuels to renewable energy sources, reducing coal combustion, and implementing laws and policies to control and prevent pollution, especially plastic pollution, from reaching our oceans. Protecting and expanding marine protected areas is also crucial for safeguarding critical ecosystems and improving human health and well-being.

Ocean acidification

Malnutrition and Poisoning

Furthermore, ocean acidification can increase the bioavailability of certain pollutants, such as mercury and other heavy metals, leading to higher levels of contamination in seafood. It can also modify the abundance and toxicity of harmful algal blooms, increasing the risk of poisoning from shellfish consumption.

Respiratory Issues

Mental Health Impacts

The loss of habitats and access to marine environments due to ocean acidification can disrupt nature-based recreational activities and social connections, negatively impacting mental health. Additionally, the decline in the availability and nutritional value of seafood can affect livelihoods, causing unemployment and financial pressures, further contributing to mental health issues.

Development of Medical Resources

The loss of marine biodiversity due to ocean acidification reduces opportunities for the development of new medicines. Coral reefs, for example, are a significant source of new marine natural products, but they are vulnerable to the effects of acidification.

To mitigate the impacts of ocean acidification on human health, it is crucial to implement strategies to reduce CO2 emissions and adapt to changing ocean conditions. This includes conserving biodiversity, restoring ecosystems, monitoring and managing water quality, and adapting human activities to changing ocean conditions.

Plastic pollution

One of the biggest concerns with plastic pollution is its persistence in the environment. Unlike other materials, plastic does not completely degrade; instead, it breaks down into smaller fragments when exposed to sunlight, ocean waves, or consumption by animals. These microplastics, measuring less than 5mm in size, are impossible to remove from the environment with current technologies. They can be ingested by marine organisms, leading to harmful effects such as blocked digestive tracts, reduced appetite, and altered feeding behavior, ultimately resulting in decreased growth and reproductive output.

The presence of microplastics in marine organisms has direct implications for human health, as these contaminated seafood options frequently end up on our dinner plates. Studies have detected microplastics in various seafood items, including fish, shrimp, mussels, and oysters. While the direct impact of microplastics on human health remains largely unknown, scientists suspect that the toxic chemicals associated with plastics can accumulate in the environment and travel up the food chain, potentially reaching humans.

Additionally, the chemicals and additives used in plastic production pose a significant risk to human health. These chemicals, such as flame retardants, dyes, and endocrine disruptors, can interfere with normal hormone function and have been linked to various health issues, including cancer, reproductive difficulties, behavioural disorders, and developmental issues in children. The pervasive nature of plastic pollution, with its presence in even the most remote areas of the Arctic and Antarctic, underscores the urgency of addressing this global crisis.

To mitigate the impacts of plastic pollution on human health, it is essential to reduce plastic production and consumption, improve waste management practices, and promote recycling and reusable alternatives. Individual actions, such as reducing single-use plastic consumption and properly disposing of plastic waste, can collectively make a significant difference in tackling this global issue.

Pharmaceutical waste

Various pharmaceutical compounds, such as antihypertensive drugs, steroids, antibiotics, and hormones, are used extensively to treat different diseases. However, the disposal of these unused medicines is often not done properly, and they are extremely toxic to living organisms. Expired and unused medicines are often discarded in household waste or flushed down the toilet or sink, which can contaminate water supplies and negatively impact the environment.

In many countries, there are no guidelines or regulations for the disposal of medications by the public, and even in countries with take-back programs, these are often not sufficiently effective. This is influenced by a lack of education or ineffective education on proper pharmaceutical disposal.

The improper disposal of pharmaceuticals can have serious consequences for human health and the environment. It is important to reduce excessive drug consumption and develop systems for the collection of unused or expired medicines. Proper management of pharmaceutical waste requires separating and storing wastes at the point of generation, and forecasting the amount of waste generated for budgeting and optimization of waste management practices.

Healthcare facilities generate 3% of pharmaceutical waste globally, and their disposal is alarming as they produce large quantities of waste and by-products. In developing countries, the proper disposal of hazardous wastes, including pharmaceuticals, remains a significant challenge, and there are often no established medication waste management programs.

The increased consumption of pharmaceuticals has led to a higher risk of pharmaceutical discharge and waste entering the environment during consumption and disposal. Poor management of healthcare waste can cause serious problems for healthcare personnel, waste workers, patients, and the general public.

To address these issues, it is crucial to implement regular monitoring of prescribed medicines, their handling, consumption, and disposal practices. Additionally, appropriate inventory management and the development of clear healthcare waste management plans and policies are recommended.

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