Impactof Environment on Public Health
Theenvironmental agent of interest is human activities, while thevector-borne disease is malaria. In this regard, the chart aboveillustrates a series of steps in which an environmental agent (humanactivities) affects the environment (escalate the prevalence ofmalaria). As can be seen, the cycle starts with human activities suchas agriculture and industrial emissions, which pollute theenvironment in different ways. Some of the forms of pollution includeemissions of greenhouse gases, which cause global warming.Consequently, global warming causes adverse climatic conditions suchas increased temperatures, precipitation, and humidity that form anenvironment conducive for improved parasite and vector activities,manifested regarding improved rate of reproduction, incubation, anddisease transmission. In the end, the interaction between theseelements results in the outbreak of malaria disease.
1.Identify the vector-borne disease
Malariais a life-threatening vector-borne disease whose common mode oftransmission is Anopheles mosquitoes through bites. As Bartoloniand Zammarchi (2012) notes, theinfected mosquitoes contain Plasmodium, which is a parasiteresponsible for causing malaria. The mosquito becomes a carrier ofthe parasite through contact with any Plasmodium-infestedenvironments such as water ponds, infected humans, and rodents. Whenthe mosquitoes bite the human, they release the parasites into thebloodstream. Once in the bloodstream, the parasites find their wayinto the liver where they mature. The parasites then find their wayinto the bloodstream, where they enter the red blood cells, grow, andcause the infected red blood cells to burst. The continued entry intothe red blood cells results in adverse health symptoms such asnausea, shaking chills, high fever, headache, anemia, vomiting, anddiarrhea.
Whilemalaria is prevalent in subtropical areas because the region is anideal habitat for the parasites, the statistics on the burden ofmalaria on global populations are alarming. According to World HealthOrganization statistics (WHO, 2015), for instance, a half of theworld’s population (3.2 billion people) is at risk of malariainfection. In 2015, the incidences of malaria were over 214 millioninfections, resulting in over 438, 000 related deaths.Despite the fact that malaria prevention and control measures havebeen vibrant and resulted in a reduction of 60 percent of mortalityrates, Sub-Saharan African population continues to sufferdisproportionately from malaria burden.In particular, Sub-Saharan African population accounted for 89percent and 91 percent of the global malaria infections and deaths,respectively. Interestingly, these statistics are amid concerns thatcurrent malaria infections are exacerbated by changes in theenvironmental conditions. In this regard, malaria infections havefar-reaching consequences on human health.
2.Explain in detail the factors contributing to global warming
Severalfactors contribute to global warming. First, it is noteworthy thatglobal warming is primarily a process characterized by piling ofgreen gases in the atmosphere, which then act as a blanket that trapsheat and limits it from leaving the earth. The consequence of thisheat-trapping process is the increase in the earth’s averagetemperatures (Smith,Wahlen & Mastroianni, 2012).The typical green gases responsible for global warming include Carbondioxide, Chlorofluorocarbons,Methane, Nitrous oxide, ozone, and water vapor. Inthis regard, any attempt of understanding the factors contributing toglobal warming arguably need to start by considering processes thatproduce the green gases.
Theseescalating emissions of these greenhouse gases into the atmosphereare particularly attributed to various forms of human activities(Canadell,Le Quere & Raupach etal.,2014).Human activities such as burning fossil fuels (natural gas, oil, andcoal) or cutting and burning forests emit carbon dioxide gas into theatmosphere. Moreover, agriculture, industrial emission and certainpractices of managing wastes release nitrousoxide and methane, among other greenhouse gases, into the atmosphere.Indeed, Smith,Wahlen, and Mastroianni (2012)notes that wastewater management, energy production, transport,domestic pollution, industrial emission, agriculture and forestryaccount for 2.8 percent, 25.9 percent, 13.1 percent, 7.9 percent,19.4 percent, 13.5 percent and 17.4 percent, respectively.
Globalwarming has also been aggravated by cutting down of trees forsettlement, agriculture, and other human activities. This view issupported by the discussion byCanadell,Le Quere & Raupach etal.,(2014) that, sincetrees act as carbon sinks, reduced forest cover implies that asignificant volume of carbon dioxide will reach the atmosphere withminimum tree abstraction.
3.Describe the effect of global warming on the incidence and prevalenceof the disease.
Ashas been noted earlier, global warming is mostly characterized byincreased average global temperatures, leading to climate change.Therefore, an understanding of the ways global warming affects theprevalence of malaria needs to consider various aspects of climatechange that affect components of malaria pathway. In general, thereis evidence that global warming has a significant impact on malariainfections, and this notably has to do with increased temperature andhumidity.
Asdocumented by Rollbackmalaria (2015), for instance, a warmenvironment has a positive impact on the incubation period onparasites, as well as vector transmission. The reproduction andactivity of species of mosquitoes that transmit malaria, such asAnophelesfunestus,Aedesaegypti,Anophelesgambiae,Culexquinquefasciatusand Anopholesdarling,are sensitive to temperature changes. Shortened larva maturationoften accompanies an increase in water temperature, consequentlyresulting in increased capacity for reproduction of a higher numberof offspring on the course of the period of transmission. Moreover,according to Elis(2014),increases in temperatures create an enabling environment formosquitoes to digest food with relative ease, consequently resultingin improved speed and frequency of feeding that culminates to a highrate of transmissions of vectors. Besides, the incubation ofmalaria-causing parasites within the female mosquitoes takes arelatively short time in warm temperatures, contributing to asignificant number of infective vectors.
Apartfrom the change of temperatures, the changes in precipitationaccompanying global warming also influence the activity of thevectors (WHO,2014).In particular, the increase in the amounts of precipitation typicallyenhances the number of breeding and resting sites formalaria-transmitting vectors.
BartoloniA, & Zammarchi L (2012). "Clinical aspects of uncomplicatedand severe malaria". MediterraneanJournal of Hematology and Infectious Diseases.4(1): e2012026.
Canadell,J. G. Le Quere, C. Raupach, M. R. Field, C. B. Buitenhuis, E. T.Ciais, P. Conway, T. J. Gillett, N. P. Houghton, R. A. Marland,G. (2014). Contributions to accelerating atmospheric CO2growth from economic activity, carbon intensity, and efficiency ofnatural sinks. Proc.Natl. Acad. Sci. U.S.A.104(47): 18866–70.
Elis,M. (2014). Couldglobal warming push malaria to higher elevations?Retrieved from http://www.medicalnewstoday.com/articles/273736.php
Rollbackmalaria(2015). ClimateChange and Malaria.Retrieved fromhttp://www.rollbackmalaria.org/files/files/about/SDGs/RBM_Climate_Change_Fact%20Sheet_170915.pdf
Smith,J., Wahlen, M. & Mastroianni, D. (2012). "The CO2concentration of air trapped in GISP2 ice from the Last GlacialMaximum-Holocene transition". GeophysicalResearch Letters.24(1): 1–4.
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WHO(2015). FactSheet: World Malaria Report 2015.Retrieved fromhttp://www.who.int/malaria/media/world-malaria-report-2015/en/