scholarly journals Mercury, Food Webs, and Marine Mammals: Implications of Diet and Climate Change for Human Health

2005 ◽  
Vol 113 (5) ◽  
pp. 521-526 ◽  
Author(s):  
Shawn Booth ◽  
Dirk Zeller
Keyword(s):  
Climate Change ◽  
Food Webs ◽  
Human Health ◽  
Marine Mammals

Methylmercury biogeochemistry: a review with special reference to Arctic aquatic ecosystems

2014 ◽  
Vol 22 (3) ◽  
pp. 229-243 ◽  
Author(s):  
Igor Lehnherr
Keyword(s):  
Food Webs ◽  
Water Column ◽  
Human Health ◽  
Bottom Sediments ◽  
Aquatic Ecosystems ◽  
Marine Mammals ◽  
Primary Source ◽  
The Arctic ◽  
Arctic Biota

There has been increasing concern about mercury (Hg) levels in marine and freshwater organisms in the Arctic, due to the importance of traditional country foods such as fish and marine mammals to the diet of Northern Peoples. Due to its toxicity and ability to bioaccumulate and biomagnify in food webs, methylmercury (MeHg) is the form of Hg that is of greatest concern. The main sources of MeHg to Arctic aquatic ecosystems, the processes responsible for MeHg formation and degradation in the environment, MeHg bioaccumulation in Arctic biota and the human health implications for Northern Peoples are reviewed here. In Arctic marine ecosystems, Hg(II) methylation in the water column, rather than bottom sediments, is the primary source of MeHg, although a more quantitative understanding of the role of dimethylmercury (DMHg) as a MeHg source is needed. Because MeHg production in marine waters is limited by the availability of Hg(II), predicted increases in Hg(II) concentrations in oceans are likely to result in higher MeHg concentrations and increased exposure to Hg in humans and wildlife. In Arctic freshwaters, MeHg concentrations are a function of two antagonistic processes, net Hg(II) methylation in bottom sediments of ponds and lakes and MeHg photodemethylation in the water column. Hg(II) methylation is controlled by microbial activity and Hg(II) bioavailability, which in turn depend on interacting environmental factors (temperature, redox conditions, organic carbon, and sulfate) that induce nonlinear responses in MeHg production. Methylmercury bioaccumulation–biomagnification in Arctic aquatic food webs is a function of the MeHg reservoir in abiotic compartments, as well as ecological considerations such as food-chain length, growth rates, life-history characteristics, feeding behavior, and trophic interactions. Methylmercury concentrations in Arctic biota have increased significantly since the onset of the industrial age, and in some populations of fish, seabirds, and marine mammals toxicological thresholds are being exceeded. Due to the complex connection between Hg exposure and human health in Northern Peoples—arising from the dual role of country foods as both a potential Hg source and a nutritious, affordable food source with many physical and social health benefits—-reductions in anthropogenic Hg emissions are seen as the only viable long-term solution.

scholarly journals Florida’s Harmful Algal Bloom (HAB) Problem: Escalating Risks to Human, Environmental and Economic Health With Climate Change

2021 ◽  
Vol 9 ◽  
Author(s):  
Cynthia Ann Heil ◽  
Amanda Lorraine Muni-Morgan
Keyword(s):  
Climate Change ◽  
Human Health ◽  
Ocean Circulation ◽  
Algal Blooms ◽  
Marine Mammals ◽  
Harmful Algal Bloom ◽  
Climate Change Impacts ◽  
The State ◽  
Economic Health ◽  
Hab Species

Harmful Algal Blooms (HABs) pose unique risks to the citizens, stakeholders, visitors, environment and economy of the state of Florida. Florida has been historically subjected to reoccurring blooms of the toxic marine dinoflagellate Karenia brevis (C. C. Davis) G. Hansen & Moestrup since at least first contact with explorers in the 1500’s. However, ongoing immigration of more than 100,000 people year–1 into the state, elevated population densities in coastal areas with attendant rapid, often unregulated development, coastal eutrophication, and climate change impacts (e.g., increasing hurricane severity, increases in water temperature, ocean acidification and sea level rise) has likely increased the occurrence of other HABs, both freshwater and marine, within the state as well as the number of people impacted by these blooms. Currently, over 75 freshwater, estuarine, coastal and marine HAB species are routinely monitored by state agencies. While only blooms of K. brevis, the dinoflagellate Pyrodinium bahamense (Böhm) Steidinger, Tester, and Taylor and the diatom Pseudo-nitzschia spp. have resulted in closure of commercial shellfish beds, other HAB species, including freshwater and marine cyanobacteria, pose either imminent or unknown risks to human, environmental and economic health. HAB related human health risks can be classified into those related to consumption of contaminated shellfish and finfish, consumption of or contact with bloom or toxin contaminated water or exposure to aerosolized HAB toxins. While acute human illnesses resulting from consumption of brevetoxin-, saxitoxin-, and domoic acid-contaminated commercial shellfish have been minimized by effective monitoring and regulation, illnesses due to unregulated toxin exposures, e.g., ciguatoxins and cyanotoxins, are not well documented or understood. Aerosolized HAB toxins potentially impact the largest number of people within Florida. While short-term (days to weeks) impacts of aerosolized brevetoxin exposure are well documented (e.g., decreased respiratory function for at-risk subgroups such as asthmatics), little is known of longer term (>1 month) impacts of exposure or the risks posed by aerosolized cyanotoxin [e.g., microcystin, β-N-methylamino-L-alanine (BMAA)] exposure. Environmental risks of K. brevis blooms are the best studied of Florida HABs and include acute exposure impacts such as significant dies-offs of fish, marine mammals, seabirds and turtles, as well as negative impacts on larval and juvenile stages of many biota. When K. brevis blooms are present, brevetoxins can be found throughout the water column and are widespread in both pelagic and benthic biota. The presence of brevetoxins in living tissue of both fish and marine mammals suggests that food web transfer of these toxins is occurring, resulting in toxin transport beyond the spatial and temporal range of the bloom such that impacts of these toxins may occur in areas not regularly subjected to blooms. Climate change impacts, including temperature effects on cell metabolism, shifting ocean circulation patterns and changes in HAB species range and bloom duration, may exacerbate these dynamics. Secondary HAB related environmental impacts are also possible due to hypoxia and anoxia resulting from elevated bloom biomass and/or the decomposition of HAB related mortalities. Economic risks related to HABs in Florida are diverse and impact multiple stakeholder groups. Direct costs related to human health impacts (e.g., increased hospital visits) as well as recreational and commercial fisheries can be significant, especially with wide-spread sustained HABs. Recreational and tourism-based industries which sustain a significant portion of Florida’s economy are especially vulnerable to both direct (e.g., declines in coastal hotel occupancy rates and restaurant and recreational users) and indirect (e.g., negative publicity impacts, associated job losses) impacts from HABs. While risks related to K. brevis blooms are established, Florida also remains susceptible to future HABs due to large scale freshwater management practices, degrading water quality, potential transport of HABs between freshwater and marine systems and the state’s vulnerability to climate change impacts.

scholarly journals Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pianpian Wu ◽  
Martin J. Kainz ◽  
Fernando Valdés ◽  
Siwen Zheng ◽  
Katharina Winter ◽  
...  
Keyword(s):  
Climate Change ◽  
Fatty Acids ◽  
Organic Matter ◽  
Food Webs ◽  
Essential Fatty Acids ◽  
Trophic Levels ◽  
Climate Change Scenarios ◽  
Essential Nutrients ◽  
Aquatic Food Webs ◽  
Aquatic Food

AbstractClimate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of food webs (i.e. seston; the most edible plankton size for zooplankton) in subalpine lake ecosystems. The interaction of higher temperature and tDOM increased the burden of MeHg in seston (< 40 μm) and larger sized plankton (microplankton; 40–200 μm), while the MeHg content per unit biomass remained stable. However, PUFA decreased in seston, but increased in microplankton, consisting mainly of filamentous algae, which are less readily bioavailable to zooplankton. We revealed elevated dietary exposure to MeHg, yet decreased supply of dietary PUFA to aquatic consumers with increasing temperature and tDOM supply. This experimental study provides evidence that the overall food quality at the base of aquatic food webs deteriorates during ongoing climate change scenarios by increasing the supply of toxic MeHg and lowering the dietary access to essential nutrients of consumers at higher trophic levels.

scholarly journals Climate Change and Health Preparedness in Africa: Analysing Trends in Six African Countries

2021 ◽  
Vol 18 (9) ◽  
pp. 4672
Author(s):  
Samuel Kwasi Opoku ◽  
Walter Leal Filho ◽  
Fudjumdjum Hubert ◽  
Oluwabunmi Adejumo
Keyword(s):  
Public Health ◽  
Climate Change ◽  
South Africa ◽  
Human Health ◽  
Health Systems ◽  
Health Professionals ◽  
Health Problems ◽  
Sub Saharan Africa ◽  
Basic Knowledge ◽  
African Countries

Climate change is a global problem, which affects the various geographical regions at different levels. It is also associated with a wide range of human health problems, which pose a burden to health systems, especially in regions such as Africa. Indeed, across the African continent public health systems are under severe pressure, partly due to their fragile socioeconomic conditions. This paper reports on a cross-sectional study in six African countries (Ghana, Nigeria, South Africa, Namibia, Ethiopia, and Kenya) aimed at assessing their vulnerabilities to climate change, focusing on its impacts on human health. The study evaluated the levels of information, knowledge, and perceptions of public health professionals. It also examined the health systems’ preparedness to cope with these health hazards, the available resources, and those needed to build resilience to the country’s vulnerable population, as perceived by health professionals. The results revealed that 63.1% of the total respondents reported that climate change had been extensively experienced in the past years, while 32% claimed that the sampled countries had experienced them to some extent. Nigerian respondents recorded the highest levels (67.7%), followed by Kenya with 66.6%. South Africa had the lowest level of impact as perceived by the respondents (50.0%) when compared with the other sampled countries. All respondents from Ghana and Namibia reported that health problems caused by climate change are common in the two countries. As perceived by the health professionals, the inadequate resources reiterate the need for infrastructural resources, medical equipment, emergency response resources, and technical support. The study’s recommendations include the need to improve current policies at all levels (i.e., national, regional, and local) on climate change and public health and to strengthen health professionals’ skills. Improving the basic knowledge of health institutions to better respond to a changing climate is also recommended. The study provides valuable insights which may be helpful to other nations in Sub-Saharan Africa.

Water Security and Human Health in Relation to Climate Change

2021 ◽  
pp. 1-21
Author(s):  
Ravishankar Kumar ◽  
Prafulla Kumar Sahoo ◽  
Sunil Mittal
Keyword(s):  
Climate Change ◽  
Human Health ◽  
Water Security

scholarly journals A Transdisciplinary Approach to Address Climate Change Adaptation for Human Health and Well-Being in Africa

2021 ◽  
Vol 18 (8) ◽  
pp. 4258
Author(s):  
Caradee Yael Wright ◽  
Candice Eleanor Moore ◽  
Matthew Chersich ◽  
Rebecca Hester ◽  
Patricia Nayna Schwerdtle ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Health ◽  
Climate Change Adaptation ◽  
Systems Approach ◽  
Health Sector ◽  
Well Being ◽  
World Health ◽  
Economic Policies ◽  
Comprehensive Health ◽  
African Context

The health sector response to dealing with the impacts of climate change on human health, whether mitigative or adaptive, is influenced by multiple factors and necessitates creative approaches drawing on resources across multiple sectors. This short communication presents the context in which adaptation to protect human health has been addressed to date and argues for a holistic, transdisciplinary, multisectoral and systems approach going forward. Such a novel health-climate approach requires broad thinking regarding geographies, ecologies and socio-economic policies, and demands that one prioritises services for vulnerable populations at higher risk. Actions to engage more sectors and systems in comprehensive health-climate governance are identified. Much like the World Health Organization’s ‘Health in All Policies’ approach, one should think health governance and climate change together in a transnational framework as a matter not only of health promotion and disease prevention, but of population security. In an African context, there is a need for continued cross-border efforts, through partnerships, blending climate change adaptation and disaster risk reduction, and long-term international financing, to contribute towards meeting sustainable development imperatives.

Major climate change-induced risks to human health in South Africa

2021 ◽  
pp. 110973
Author(s):  
Caradee Y. Wright ◽  
Thandi Kapwata ◽  
David Jean du Preez ◽  
Bianca Wernecke ◽  
Rebecca M. Garland ◽  
...  
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Human Health
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