The Role of Environmental Health on Pandemics: a review report

Hunachew Beyene, PhD, Assi Prof, Hawassa university Department of Environmental Health; Amanuel Ejeso (MSc, Lecturer), Hawassa University, Department of Environmental Health; Wondayehu Wubie, FMOH, Environmental Health Directorate.

Background

From longstanding to emerging human health hazards, environmental factors are a root cause for a significant burden of death, disease and disability globally and particularly in developing countries. Most of the devastating pandemics in the world occurred as a result of the changes in the environment and the niches of the organisms. The transmission of most of the pandemics can be reduced by the application of environmental health measures. Therefore, readily available and pertinent information would be helpful for managers and policymakers to estimate the health impacts associated with their decisions. The assessment aimed to generate evidence regarding the contribution of environmental health in the prevention and control of pandemics including Covid-19.

Method

The assessment is based on document review available on the internet. Given that the services of environmental health are diverse and there are several pandemics, we used several combinations of worlds to search articles in the net, namely Hinari, Google Scholar, and other search engines. The document selection strategies were conducted by experts in the field.  The generated documents were screened based on their relevance in holding the factors and diseases of interest. The discussion was then made by content analysis.

Result

Throughout human history, several pandemics which caused the death of millions of people occurred in the world. The main ones were: the Black Death wiped out over half of Europe's population from 1346-1353, Cocoliztli epidemic (1545-1548)  killed 15 million inhabitants of Mexico and Central America, the 1918 Spanish influenza-infected more than one-third of the world’s population and killed approximately 50 million people, the famous Spanish Flu (1918-1920) which killed an estimated 100 million people, and the recently discovered COVID 19 which killed more than 2 million people. The causative agents of most of the major pandemics are viral except for the bacteria Yersinia pestis and Vibrio cholera which is responsible for the Black Death and cholera respectively. Most of the pandemics which occurred in human history have got environmental transmission routes, mainly through the respiratory system through droplet, contact and airborne routes. The Black Death was transmitted through flea bites, contact with contaminated fluid or tissue and infectious droplets. Cholera is a typical example of water and foodborne disease. Zika Virus epidemic transmitted mainly through the bite of an infected Aedes aegypti. The nature of transmission of the agents entails that the prevention can be achieved through the application of environmental health measures such as water, sanitation, and hygiene, application of basic infection prevention and control methods, good housing, standard food hygiene, prevention of waterborne diseases, rodents and vector control and avoidance contact with wild animals.

Conclusion and recommendation

Most of the pandemics are zoonotic origin, which implies that there has been increased human and animal interface as a result of ecosystem loss. Besides, most of the pandemics showed seasonality, impels that climate factors have got a role in their dynamics. Environmental Health interventions consistently reduced both the risk of disease and the risk of transmission. Various governmental and non-governmental stakeholders at various levels need to increase the scientific contribution of environmental health services by supporting through training. Environmental health services need to be supported by policies and need to be mainstreamed in various sectors. Further research can be conducted using a single outcome and contribution of a factor.