Drinking-water nitrate and cancer risk: A systematic review and meta-analysis.

BACKGROUND: Nitrate is an inorganic compound that occurs naturally in all surface and groundwater, although higher concentrations tend to occur only where fertilizers are used on the land. The regulatory limit for nitrate in public drinking water supplies was set to protect against infant methemoglobinemia, but other health effects were not considered. Risk of specific cancers and congenital disabilities may be increased when the nitrate is ingested, and nitrate is reduced to nitrite, which can react with amines and amides by nitrosation to form N-nitroso compounds which are known animal carcinogens. This study aims to evaluate the association between nitrate ingested through drinking water and the risk of developing cancers in humans. METHODS: We performed a systematic review following PRISMA and MOOSE guidelines. A literature search was performed using PubMed, EMBASE, the Cochrane Library databases, Web of Science and Google Scholars in the time-frame from their inception to January 2020, for potentially eligible publications. STATA version 12.0 was used to conduct meta-regression and a two-stage meta-analysis. RESULTS: A total of 48 articles with 13 different cancer sites were used for analysis. The meta-regression analysis showed stomach cancer had an association with the median dosage of nitrate from drinking water (t = 3.98, p = 0.0001, and adjusted R-squared = 50.61%), other types of cancers didn't show any association. The first stage of meta-analysis showed there was an association only between the risk of brain cancer & glioma (OR = 1.15, 95% CI: 1.06, 1.24) and colon cancer (OR = 1.11, 95% CI: 1.04, 1.17) and nitrate consumption in the analysis comparing the highest ORs versus the lowest. The 2nd stage showed there was an association only between the risk colon cancer (OR = 1.14, 95% CI: 1.04, 1.23) and nitrate consumption in the analysis comparing all combined higher ORs versus the lowest. CONCLUSION: This study showed that there is an association between the intake of nitrate from drinking water and a type of cancer in humans. The effective way of controlling nitrate concentrations in drinking water is the prevention of contamination (water pollution). Further research work on this topic is needed.

An Overview of Healthcare Systems in Comoros: The Effects of Two Decades of Political Instability.

Background: There is ongoing scientific evidence pointing out the adverse effects of conflict on population health and development. Union of Comoros has experienced nearly two decades of political instability and military rule. This comprehensive review was carried out to ask whether the health crisis in Comoros is attributable to the consequences of the chronic political instability. Methods: This study involved a series of semi-structured interviews with key informants complemented by a comprehensive literature search of electronic databases and grey literature. A literature search was performed using all identified keywords associated with health indicators in Comoros to identify potential eligible publications in both English and French from 1975 to July 2020. Results: The analysis demonstrated that political instability and lack of proper leadership from the Government undermine the establishment of health policies which contributed dramatically to the decline in health performance. Additionally, the resurgence and emergence of old and new diseases such as cholera, chikungunya, malaria, HIV/AIDS as indicators of inadequate health services were most likely during political turmoil. Data also showed an out-migration of the health workforce and an increased overseas medical treatment demand, which indicate less attractive working conditions and weak health systems in the country. Meanwhile, an increasing performance of health status indicators was observed after the comprehensive peace process of the 2000-Fomboni Declaration. Conclusions: The chronic political instability in Comoros has contributed to the health crisis facing the Union of Comoros. It has hampered the implementation of proper institutions, which might guarantee the socio-economic development and prosperity of the population. Further studies were needed to evaluate the health burden associated with the two decades of political instability and military rule.

A Comparative Study of the Health Care Delivery Systems in the Indian Ocean: What can Comoros Islands Learn from Mauritius and Seychelles?

In recent years, there have been significant efforts to examine the organization and performance of health systems. This study's main purpose is to compare health systems and analyze the health status of the citizens of Comoros, Mauritius, and Seychelles, with the intention of providing policy recommendations for Comoros. Peer-reviewed studies and reports published by non-governmental organizations and international agencies were systematically collected through large database searches, filtered through methodological inclusion criteria, and organized into the World Health Organization (WHO) building blocks framework. The literature review demonstrates that health outcomes have dramatically improved over the past decades in Mauritius and Seychelles but not in Comoros. As of 2015, Mauritius and Seychelles were among the few African countries to have achieved almost all the Millennium Development Goals, whereas Comoros still struggles to reduce child mortality and improve maternal health. In contrast, the total health expenditure of the three island states, as a percentage of gross domestic product (GDP), seemed similar over the studied time period.