Human Health and Ocean Pollution

Abstract

Methods: Topic-focused reviews that examine the effects of ocean pollution on human health, identify gaps in knowledge, project future trends, and offer evidence-based guidance for effective intervention. Environmental Findings: Pollution of the oceans is widespread, worsening, and in most countries poorly controlled. It 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% arises from land-based sources. It reaches the oceans through rivers, runoff, atmospheric deposition and direct discharges. It is often heaviest near the coasts and most highly concentrated along the coasts of low-and middle-income countries. Plastic is a rapidly increasing and highly visible component of ocean pollution, and an estimated 10 million metric tons of plastic waste enter the seas each year. Mercury is the metal pollutant of greatest concern in the oceans; it is released from two main sources-coal combustion and small-scale gold mining. Global spread of industrialized agriculture with increasing use of chemical fertilizer leads to extension of Harmful Algal Blooms (HABs) to previously unaffected regions. Chemical pollutants are ubiquitous and contaminate seas and marine organisms from the high Arctic to the abyssal depths. Ecosystem Findings: Ocean pollution has multiple negative impacts on marine ecosystems, and these impacts are exacerbated by global climate change. Petroleum-based pollutants reduce photosynthesis in marine microorganisms that generate oxygen. Increasing absorption of carbon dioxide into the seas causes ocean acidification, which destroys coral reefs, impairs shellfish development, dissolves calcium-containing microorganisms at the base of the marine food web, and increases the toxicity of some pollutants. Plastic pollution threatens marine mammals, fish, and seabirds and accumulates in large mid-ocean gyres. It breaks down into microplastic and nanoplastic particles containing multiple manufactured chemicals that can enter the tissues of marine organisms, including species consumed by humans. Industrial releases, runoff, and sewage increase frequency and severity of HABs, bacterial pollution, and anti-microbial resistance. Pollution and sea surface warming are triggering poleward migration of dangerous pathogens such as the Vibrio species. Industrial discharges, pharmaceutical wastes, pesticides, and sewage contribute to global declines in fish stocks. Human Health Findings: Methylmercury and PCBs are the ocean pollutants whose human health effects are best understood. Exposures of infants in utero to these pollutants through maternal consumption of contaminated seafood can damage developing brains, reduce IQ and increase children's risks for autism, ADHD and learning disorders. Adult exposures to methylmercury increase risks for cardiovascular disease and dementia. Manufactured chemicals-phthalates, bisphenol A, flame retardants, and perfluorinated chemicals...

Cellular and Molecular Mechanisms Mediating Methylmercury Neurotoxicity and Neuroinflammation

“…Affected individuals exhibited symptoms that indicate neurological alterations which include ataxia, visual field and hearing alterations, dysarthria, paresthesias in the distal parts of extremities, disequilibrium, gait impairment, tremors, muscle weakness, atypical eye movement, and seizures [28][29][30][31]33]. Occasionally, mental disorders and disturbances of smell and taste were also present [28].…”

“…Occasionally, mental disorders and disturbances of smell and taste were also present [28]. Beyond injuries of the nervous system (the primary target of MeHg), other organs suffer minor damages, including kidneys and liver, pancreatic islet alterations, lymph node atrophy, and gastrointestinal tract inflammation [5,33]. Ultimately, MeHg led to the death of some poisoned locals [29].…”

Coastlines, Coastal Cities, and Climate Change: A Perspective on Urgent Research Needs in the United States

“…How can efforts to model climate change effects be coordinated more effectively with, and communicated, to coastal communities and other users (Smith et al, 2019) 24. How can we minimize health threats to humans from harmful algal blooms, Vibrio bacteria, marine pollution, and other risks that are increasing rapidly in response to rising temperatures, sea level rise, and other global change factors (Fleming et al, 2014;Scott et al, 2019;Landrigan et al, 2020;Sandifer et al, 2021a)? (N) 25.…”

Pollutants in the South Atlantic Ocean: Sources, Knowledge Gaps and Perspectives for the Decade of Ocean Science

“…Since they don't degrade in the environment, bacteria reproduce and can amplify antibiotic resistance genes and pass them through the microbial community and, thus, can represent a critical environmental and human health risk (Pruden et al, 2006). The introduction from land-based allochthonous bacteria carrying resistance genes may account for the acquisition of antimicrobial resistance by indigenous pathogens such as Vibrio (Landrigan et al, 2020). Developing countries around the SA lack infrastructure for waste and water treatment and to recycle waste to prevent epidemics.…”