Minamata Disease

A Tale of Minamata Bay: The Dancing Cat Disease

Minamata disease is a subtype of methylmercury poisoning that was caused by industrial pollution, also called effluent, which was dumped into Minamata Bay from 1932 to 1968 by the Chisso factory, a manufacturing plant located in Kumamoto Prefecture, Japan (Yorifuji, 2020). Because of bioaccumulation and biomagnification, methylmercury- a toxic byproduct of acetaldehyde production- worked its way up the food chain and into the brain by contaminating seafood, which is commonly consumed in Japan. Shortly thereafter, fish, birds, rats, and cats began to violently seize and shake so much that they appeared to be dancing, hence the name, “The Dancing Cat Disease” was popularized (Eto et al., 2001). Minamata disease was not officially recognized until May 1st, 1956, when “a high incidence of central nervous system disease of unknown etiology” was reported to the local health department after two young sisters fell ill; by August 1956, 13 out of the 34 cases had died (Yorifuji, 2020). Another 54 cases were identified between 1953 and 1956, along with similar outbreaks in other prefectures (Eto, 1997). However, organic mercury was not suspected as a cause until July 14th, 1959 (Eto et al., 2001).

The study question, “Are current residents or neighbors of Minamata still at an increased risk of methylmercury poisoning from eating fish in the bay?” was chosen because it is relevant and measurable, as the Japanese government failed to intervene despite studies indicating that action was needed, and nearly 3,000 people died as a result (Eto, 1997). The Kumamoto Prefecture tried to warn locals through the Food Sanitation Act after a positive relationship was found between fishing and Minamata disease in March 1957, but Ministry of Health and Welfare of Japan denied their request due to a lack of evidence on September 11th, 1957, so residents continued to eat local fish until the Japanese government accepted a causal relationship between the Chisso factory and Minamata disease in 1968; only 2,282 people had been diagnosed by January 2019, but many have not received recognition or compensation (Yorifuji, 2020).

Selection of Study Approach: 1 page

(thorough explanation of why the study approach was selected)

The study approach that will be utilized is a systematic review to identify if there is still an increased risk for methylmercury poisoning from the consumption of fish. A systematic review is the most applicable study approach because of the flexibility allowed for utilizing past quantitative data on the topic of Minamata disease. A quantitative approach is being implemented to study the variables of the exposure in relevance to the Minamata cases reported. There will be multiple factors examined by other studies to conclude if the current residents are still at an increased risk of exposure. The study question that guided the research is important to validate if there is still a relationship between the population and source of exposure. For this study, the population being examined is the residents of Minamata Bay. The source of exposure is the fish located in Minamata Bay. To determine if there is still a risk, previous studies from reputable data sources will be utilized. For this review, scholarly articles and journals will be included to examine past data on the number of cases, and mercury levels in the sediment of Minamata Bay. To exclude any bias, areas around Minamata Bay will be included in the data analysis. The synthesis of data from the quantitative studies will convey if there is a risk of methylmercury poisoning. The studies will examine observations in the number of cases over a thirty-year span. The patterns of mercury levels contained in sediments will also be evaluated to determine if the mercury found in sediment poses a threat to the current residents.

Designing of study and collection of data: 1 page (Thorough explanation of how the study was designed and how data was collected)

The study question on Minamata disease was investigated through a systematic review approach and secondary data research in the research paper. The study's methodology encompassed various pivotal stages, such as devising criteria for inclusion, performing an exhaustive exploration of the literature, choosing pertinent publications, and extracting data for analysis. It established explicit criteria for inclusion to facilitate identifying and retrieving relevant articles and journals. The requirements encompass aspects such as the temporal placement of publication, linguistic attributes, research methodology, and pertinence to the inquiry at hand. The researchers ensured the appropriateness of the included studies for addressing the research question and providing valuable insights by establishing unambiguous criteria (Bash et al., 2021). A thorough literature review was performed to ascertain articles and journals that satisfied the predetermined criteria for inclusion. To ensure necessary research, this stage gathered relevant papers. Data extraction followed article selection. Investigation design, sample size, exposure assessment techniques, outcome measures, and noteworthy results were extracted from each investigation. This step collected consistent data from the selected research to ease further analysis and amalgamation.

The systematic investigation using peer-reviewed journals examined Minamata sickness, methylmercury exposure, and seafood consumption (Puty et al., 2019). Authorities offered actual proof for the research inquiry, and noteworthy findings and secondary data analysis complemented the literature review. Government reports, environmental assessments, health records, and other data were analyzed. We now know Minamata's methylmercury poisoning risks from secondary data. The study technique examined academic papers and journals using rigorous selection criteria, literature discovery, and reliable data retrieval (Ruggiano, & Perry, 2019). These methods allowed researchers to analyze and combine pertinent literature and data.

Designing of study and collection of data: 1 page

(thorough explanation of how the study was designed and how data was collected)

A systematic review was done, which involved articles and journals being reviewed explicitly. We created a protocol that included transparent criteria for including and excluding some articles, studies, and journals to ensure that everything has been covered so that our material provides a more comprehensive replicable, objective overview (Ranganathan & Aggarwal, 2020). Secondary data research is used for our research, expanding the research scope and enabling us to access varied samples (McCombes, 2023). Quantitative data analysis is used in the designing of the study, which will include statistical analysis, enabling the group to summarize the sample data, make estimates, and test hypotheses (McCombes, 2023). We also used the article written by Dr. Shoji Kitamura, born in 1915, was a medical doctor and a professor of Department of Public Health in the Medical School at Kumamoto University when the Minamata disease incident occurred. The article summarized findings from a very-early-phase epidemiological study carried out by researchers from Kumamoto University immediately after the Minamata disease incident was recognized on May 1, 2011 (Yorifuji, 2020). We also used the Sage Journals which provided research about the disease. People become acutely aware of environmental contamination when they learn that the fetus of a contaminated mother may suffer more serious damages. People who suffer first from the damages of environmental contamination are always those who maintain close contact with nature, particularly children and the elderly. Minamata disease brought about tragic results because the patient's central nervous system was primarily damaged (Harada, 1994). An article about Health and Minerals provided us with the research regarding the impact of environmental pollution on communities. The removal of contaminated sediments from the bay and river floor, monitoring of methylmercury levels in fish and wastewater, and other measures against environmental pollution have all been implemented as measures against environmental pollution. As a result of the clinical and protective measures implemented after the discovery of the disease, Minamata Disease appears to no longer occur in Japan ( Minamata Disease the History and Measures - Summary, n.d.).

Data Analysis: 1 page

(thorough analysis of data)

Data Analysis: 1 page (thorough analysis of data)

Through systematically reviewing various sources on the topic of Minamata disease, quantitative data pertaining to the study question, “Are current residents or neighbors of Minamata still at an increased risk of methylmercury poisoning from eating fish in the bay?” was found. “The History and Present of Minamata Disease”, is a source that contains a section on the certification of verified cases of Minamata disease in Minamata, Japan, and neighboring areas from 1973 to 2003 (Hachiya, 2006). It also includes a graph with numerical data from the Chisso Corporation that caused the disease. Hachiya explains that the graph represents the number of people in and near Minamata, Japan that were officially certified as having Minamata disease through biological testing. The bar graph includes the total number of patients with confirmed Minamata disease, (up to 1400 individuals) on its y-axis, while the x-axis includes the years 1973 to 2003. Approximately 400 patients were confirmed to have Minamata disease in 1973. In 1983, the graph shows a significant decrease in the confirmed cases of Minamata disease. In 1983 the confirmed cases were around fifty individuals. Looking forward another ten years to 1993, there were zero reported cases by the Chisso corporation. Six years later, the graph demonstrates a minuscule spike in the disease of about five individual confirmed cases of Minamata disease in 1999. From 1999 through 2003, no cases were confirmed in the area. From the data analyzed, Minamata, Japan, and surrounding areas are no longer at increased risk of Minamata disease. The disease contracted from ingesting methylmercury-infected fish and shellfish from the bay area had significantly decreased by 1991. Today, there are few records of confirmed Minamata disease cases. According to the graph analyzed, the number of cases of confirmed Minamata disease has decreased, which means that the locals in and around Minamata, Japan are at a lower risk of methylmercury poisoning today (Hachiya, 2006).

Reporting of Findings:1 page

(why a paper is appropriate to report the research) Onl y this page should be done

References

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Bash, K. L., Howell Smith, M. C., & Trantham, P. S. (2021). A systematic methodological review of hierarchical linear modeling in mixed methods research. Journal of Mixed Methods Research, 15(2), 190-211. https://journals.sagepub.com/doi/pdf/10.1177/1558689820937882

Ekino, S., Susa, M., Ninomiya, T., Imamura, K., & Kitamura, T. (2007). Minamata disease revisited: an update on the acute and chronic manifestations of methyl mercury poisoning. Journal of the neurological sciences, 262(1-2), 131-144. https://www.institute-of-mental-health.jp/thesis/pdf/thesis-02/thesis-02-18.pdf

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Eto, K., Yasutake, A., Nakano, A., Akagi, H., Tokunaga, H., Kojima, T. (2001). Reappraisal of the Historic 1959 Cat Experiment in Minamata by the Chisso Factory. The Tohoku Journal of Experimental Medicine, 194(4), 197-203. http://www.journal.med.tohoku.ac.jp/1944/TJ1944_01.pdf

Hachiya, N. (2006). Entering the Second Half of the Century: The History and Present of Minamata Disease, Japanese Medical Association Journal. https://www.med.or.jp/english/pdf/2006_03/112_118.pdf

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Ruggiano, N., & Perry, T. E. (2019). Conducting secondary analysis of qualitative data: Should we, can we, and how? Qualitative Social Work, 18(1), 81-97. https://journals.sagepub.com/doi/pdf/10.1177/1473325017700701

Ranganathan, P., & Aggarwal, R. (2020). Study designs: Part 7 - systematic reviews.

Perspectives in clinical research.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7342340/

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