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JOURNAL OF RESEARCH IN NATIONAL DEVELOPMENT VOLUME 6 NO 2, DECEMBER, 2008

PROXIMITY OF MUNICIPAL WASTE AND RATE OF HOSPITALIZATION FOR MALARIA

Edmund E. Nkwocha
Department of Environmental Technology,  Federal University Technology, Owerri.
and
Raphael O. Egejuru
Department of Pathology, Federal Medical Center, Owerri

Abstract
Epidemiological studies suggest that there may be an association between environmental exposure to waste dumpsites and malaria. The aim of this study was to test the hypothesis that residential proximity to waste dumpsites result in increased rate of hospitalization for malaria among the most vulnerable population groups such as children. A total of 160 children (n=160) between the ages of 1 and 5 years were sampled in a residential neighborhood in Owerri. Data were obtained from the parents of the subjects with the aid of a specially designed and well-structured questionnaire. After analysis with statistical tools, results show that there was a significant increase in the incidence of malaria and rate of hospitalization among children. The most affected group were those between the ages of 2 and 3 years living within a radius of less than 300 meters the dump site. These results show that municipal waste dumpsites create pathological zones in which disease vectors proliferate and pose significant dangers to human health and environment.

Keywords: Dumpsite, hospitalization, malaria, waste.


Introduction
The continued function and survival of any human society is dependent, to a large extent, on its adaptability and resilience to environmental events (Young et al, 2006). As globalization accelerates the rate and spatial scale of human–environment interaction, the distinction between natural and man-made disasters becomes blurred (Pezzoli et al, 2007). In Nigeria, solid waste management has remained one of the greatest environmental challenges of urban municipalities, gulping about 10 to 20 percent of their annual budgets (FEPA, 1999). This is partly because their phenomenal population and spatial growth are not coupled with the provision of waste treatment and disposal facilities. Consequently, urban residents have dumped their waste indiscriminately at open spaces, undeveloped plots and by road sides. There is great anxiety about environmental risks associated with poor waste management in the country. Increasingly, the public is becoming aware of environmental issues such as the potential hazards to health resulting from disposal of a wide range of wastes (Sheldon and Smith, 1995; Gatrell et al, 1995).

Goren and Hellman (2001) argue that exposure to even low levels of pollution resulting from waste accumulation can aggravate health problems especially among the most vulnerable groups. Other authorities posit that waste dumps could provide conditions in which disease vectors could persist and reproduce, although this depends on waste constituents, environmental conditions, age of the dumps and operating practices (Swan, et al, 2002; Faber and Krieg, 2001). Among these vectors are mosquitoes that cause malaria. This disease is caused by the bite of an infected female Anopheles mosquito which transmits the Plasmodium falciparum parasite into the human bloodstream; from there it travels to the liver, where it grows and multiplies from a

period of 8 days to several months and even years (Afolabi, 2006).
A number of studies have investigated the incidence of malaria all over the world (Ayala et al, 1999; Sturchler 1989; Bruce-Chewatt, 1985). It is estimated that the annual death resulting from this disease is between 1.1 and 2.7 million people out of which over one million are children under the age of five in the Sub-Saharan Africa (Ikhisemoge, 2006; Jacquiet, 2001; Snow, 1997; Coluzzi, 1997). Much attention have been focused on vulnerable groups especially children due to perceived evolution and increasing resistance of the malaria parasite to modern drugs (Hemingway, 1999; Bisseru, 1985; Gadzama, 1983). Malaria is holoendemic in Nigeria as high intensity transmission occurs all year round with rates of transmission higher in the wet season than in the dry season (Okogun, 2003). There is limited evidence from the results of all these studies to suggest that the breeding and multiplication of mosquitoes on waste dumps can lead to increase in the incidence of malaria.

This study examined the health effect of a waste dumpsite on the population living in proximity to it. It tries to establish whether there is a strong link between pathological zones created by the dumpsite and the incidence of malaria; whether the proximity of a residential area to municipal waste dumpsite has a significant influence on the rate of hospitalization of children due to malaria disease.

 

Materials and Methods
The study area is located in the South-Western fringe of Owerri Municipal in a relatively new and fast growing neighborhood called New Market. The study area was chosen for several reasons: Firstly, the area is well delineated from other residential zones in Owerri Municipal by natural and man-made features. In fact, it is bounded in the South, through South-West by Otamiri stream; in the East by Emmanuel College premises and the New

Market site, all running parallel to a major transportation route (Douglas Road), and in the North by Royce Road. Its location is therefore distinct and interesting for such a study. Secondly, although some commercial activities are practiced along the streets and major roads bordering the area, the zone is mainly residential, with a very high population density. The final reason is the willingness of residents to cooperate with anything that has to do with the dumpsite, because of its high nuisance value within the neighborhood.

However, as a result of lack of waste collection systems in the area, most residents found it most convenient to dump their waste on an undeveloped piece of land located few meters away from the nearby Otamiri stream, which in fact, serves as a source of water supply to many communities downstream (Nekede, Ihiagwa, Obinze).  Refuse has been dumped on this site for more than 15 years, on a surface area approximately 6 hectares in size, 5 meters high and uncovered. Nearly 10 tons of wastes are dumped here each day. Waste components mainly include metals, (beverage cans, ferrous materials), used papers, rags, plastics and organic materials (food remnants, decaying leaves, fruits and vegetables, etc.). All these materials provided conducive environment for the anopheles mosquitoes to breed in large numbers. The area surrounding the dumpsite is highly urbanized and mainly used for mixed residential houses made up of bungalows and high-rises not exceeding two floors. The closest buildings are located at a distance of 105 meters from the dumpsite, which shows the integration of the latter within the neighborhood.

The total population of the neighborhood is estimated at about 18,563 based on the National Population Census data of 2006. From this population which fell within a Census Enumeration Zone (CEZ), a sample of 134 families having 188 children between the ages of 1 and 5 years were randomly selected using their House Enumeration Numbers. This age range of children was chosen as they

constituted the most vulnerable groups especially to malaria disease. The choice of families was validated through field visits which helped to remove over-aged children from our sample. A total of 160 subjects were finally selected for the study (n=160). 

 It is not easy to embark on epidemiological investigation on waste-health relationships within a population in an environment fraught with paucity of data. Data used for the study were therefore obtained through surrogate methods. A well-structured questionnaire containing basic socio-economic characteristics of the children and their parents (age and sex of children, education and income status of parents, etc) was carefully prepared. Other important variables on the housing conditions of the subjects such as presence of waste bins around homes, use of mosquito nets and insecticides were all included in the questionnaire. Parents of the subjects were also asked to indicate the number of times and month of the year their children fell sick and were admitted into the hospitals, diseases they suffered from, names of hospitals visited, and their hospital card numbers. Cases were retrospectively verified in the various hospitals where the children were treated using their card numbers. Data on these variables were requested for the past 15 months preceding our visit. For easy identification and compilation by the parents, all the requested variables were enlisted in a simple matrix format. These covariates were chosen based on previous literature identifying potential risk factors for disease exposure (Tonne et al, 2007; Khitoliya, 2004; Katsouyanni et al, 2001).

The study considered one measure of exposure to malaria infection, namely; the distance between subjects from the dumpsite. Thus, in the study area, two cordon zones were carefully delineated. The first Zone designated as Zone A, has the range of a distance between 100 and 500 meters from the dumpsite. While 110 of our subjects live in this zone, the remaining 50 subjects reside in the second zone known as Zone B, which was also in the

same neighborhood but beyond 500 meters from the dumpsite. These two zones are separated from each other by Royce and Nekede Roads. Zone B may therefore be likened to as the “clean or control” zone.  

Given the limited sample size, three age groupings of the children were made (<1 year, 2-3 years and 4-5 years). To neutralize the effect of variables such as housing conditions, income and education levels of parents, etc, a logistic model was used. The exposure measures among subjects and total sample population were done using logistic regression. Risk estimates were measured in the form of Odd-Ratios (ORs). The exposure measures for malaria and rate of hospitalization among subjects were equally carried out. Analyses on the special effects of residential distance from the dumpsite and the rate of hospitalization were also made using logistic regression model in which distance was sub-divided into 100, 200, 300, 400 and 500 meters and above and included as categorical variables. Because of the sample size, the ORs were adjusted for potential confounders. Regression ANOVA and chi-square tests were used to compare major differences between the two zones. Coefficients were calculated using the Spearman rank order correlation test. Data was analyzed by SPSS for Window 10.0 (SPSS, Chicago, IL. USA)

Results   and   Discussion
The descriptive information focused mainly on the socio-economic status of the parents (income, education) as well as some variables on the children (age, sex). The average age of the children was 2.8 years. Based on the three age groupings, 54 (33.75%) of the subjects are less than 2 years old, 53 (33.13%) between 2 and 3 years, and 53 (33.13%) between 4 and 5 years old. There were 83 males (51%) and 77 females (49%) which shows almost equal representations of both sexes in the total sample. The highest number of children within the study age group per family was two while the least was one. All the families surveyed have lived in their apartments for more than

five years, indicating that the majority of the subjects have been exposed since birth. The average educational level of parents was the West African School Certificate, with an average monthly income level hovering between N15,000 and N20,000 indicating that most of the children are of poor parentage. The average household consists of 7 persons residing in a concrete dwelling of three rooms

 

properly ventilated with sufficient doors and windows. Only 9 families of the subjects (5%) used mosquito nets while the greater majority made up of 151 families or 95% of the total sample did not. Also, while132 families of the subjects (83%) did not apply insecticides within their homes only 28 families (17%) used it regularly to kill mosquitoes. All the families surveyed kept their waste bins outside their homes as shown in Table 1.


Table 1:   Descriptive characteristics of the study population and exposure
                  ( n = 160)
klk;l 


Age of children (years)            No%
;l;l' 



< 2                                           54 (33.75)
    1. 53 (33.13)                                                    
    2. kjhghg53 (33.13)

 

Income of parents (N)             No%
hfghfhg           
15,000-20,000                         98 (61.25)
21,000 – 30,000                      21 (13.12)
31,000 – 35,000                      23 (14.38)
>35,000                                   18 (11.25)
                        ghfhg
Education status of father        No/%
hghfhg           
Higher Education                     23 (14.38)
Average Education                  35 (21.87)
Lower Education                     102 (63.75)
gfhgf[[[
[[
[[[[

Education status of mother      No/%
hghfg 



Higher Education                     15 (9.36)
Average Education                  18 (11.26)
Lower Education                     127 (73.38)

 

jghhjgHousing Conditions                   No%
jhjhfg 



Well ventilated                               151 (94.38)
Poorly ventilated                             9 (5.62)
gfdfd 

Presence of bins                        No%         
jhghfg 

Yes                                                       160(100.0)
No                                                        00(0.00)
hfgfg 

hgfhjfgfhgfUse of mosquito nets                      No%
Yes                                                     9 (5.63)
No                                                      151 (94.37)
gfhgf 



Use of insecticides                          No%                                                  
hgfgYes                                                     28 (17.5)
No                                                     132(82.5)
hghjgfjh 

 

 



Data used for the study spanned for a period of 11 months as most parents could no longer remember what happened beyond this period when filling the questionnaire. However, information obtained revealed the prevalence of malaria among subjects in the two zones investigated. A trend of greater frequency was noted in Zone A in comparison with Zone B as shown in Table 2.

Table 2: Number of subjects treated for malaria in zones A and B (n =160)

 

Zone A (<200m)

Zone B (>500m)

 

 

Months

No
Treated
(F)

%

No treated (F)

%

Total

%

Oct. ‘06

57

12.6

    6

1.3

63

13.9

Nov. ‘06

47

10.3

    4

0.8

51

11.1

Dec.’06

40

8.8

    5

1.1

45

9.9

Jan. ‘07

36

7.9

    3

0.6

39

8.6

Feb. ‘07

23

5.0

    3

0.6

26

5.7

Mar. ‘07

32

7.0

    6

1.3

38

8.4

April ‘07

27

6.0

    7

1.6

34

7.5

May ‘07

43

9.5

    4

0.8

47

10.3

June ‘07

29

6.4

    4

0.8

33

7.2

July ‘07

35

7.7

    6

1.3

41

9.0

Aug. ‘07

30

6.6

    5

1.1

35

7.7

 

399

88.3

   53

11.8

452

100.0

 

 

 

 

 

 

                        Source: Field Survey 2006/2007


Among the total sample of n=160, there were 452 reported cases of malaria among the subjects within the 11-month study period. Of this total, 399 children (88.3%) were treated in

Zone A (d < 500 meters) and 53 children (11.8%) in Zone B (d>500 meters) as shown in Table 2. Medical notes revealed that the infected subjects showed symptoms of the disease (high fever, body weakness, loss of appetite, etc). Results of their blood analyses also indicated that each of the infected children had malaria parasite, though with different degrees of infection. Also, each child that suffered from the disease spent a minimum of one day in the hospital. While the highest incidence of malaria was recorded in the month of October 2006 with 63 cases (13.9%), the least incidence occurred in February 2007 with 26 cases (5.7%). About 100 serious cases of malaria were reported with a total hospitalization period of 1174 days showing an average of 2.7 days per subject as indicated in Table 3. Also, 27% of subjects in Zone A suffered double episodes, with the duration of

the illness ranging between 3 to 5 days. Only 2% of subjects in Zone B suffered double episodes of the disease. Unfortunately, there were 19 (4.2%) reported cases of death resulting from malaria which occurred among children between the ages of 2 and 3 years old, all occurring in Zone A .

The rate of malaria incidence decreased with age and was significantly higher among subjects living around the dumpsite. The rate of hospitalization was highest among children between the ages of 2 and 3 years indicating that this group was the most vulnerable. Also, the rate ratio (RR) was significantly high (6%) among subjects in Zone A than those in Zone B (0.76%). However, this ratio decreased with age in both zones. There was no significant difference in the rate of hospitalization between the two sexes in the overall sample.


Table 3: Cases of Malaria Resulting from Proximity of New Market Residential
    Area To A Waste Dumpsite.

Months

Total No. of Children Treated for Malaria

%

Serious cases

%

No. of Deaths

%

Duration of
 Hospitalization
(no of days)

%

Total
Alive

%

Oct. ‘06

63

13.9

13

2.9

2

0.4

182

15.5

61

13.5

Nov. ‘06

51

11.2

9

1.9

1

0.2

131

11.2

50

11.1

Dec.’06

45

9.9

11

2.5

2

0.4

126

10.7

43

9.5

Jan. ‘07

39

8.6

18

3.9

2

0.4

108

9.2

37

8.2

Feb. ‘07

26

5.7

7

1.5

3

0.6

61

5.2

23

5.1

Mar. ‘07

38

8.4

5

1.1

5

1.1

73

6.2

33

7.3

April ‘07

34

7.5

8

1.8

1

0.2

82

6.9

33

7.3

May ‘07

47

10.4

11

2.5

-

-

131

11.2

47

10.4

June ‘07

33

7.3

10

2.2

2

0.4

112

9.5

31

6.9

July ‘07

41

9.1

3

0.7

-

-

77

6.6

41

9.0

Aug. ‘07

35

7.7

5

1.1

1

0.2

91

7.8

34

7.5

TOTAL

452

100.0

100

22.1

19

4.2

1174

-

433

95.8

Source: Field Survey 2006/2007


The rate of hospitalization correlated positively with distance from dumpsite (0.83). The Spearman correlation coefficient calculated between rate of hospitalization and distance from dumpsite in Zone A was -1.12 (p<0.05) and was adjusted for other factors that may have contributed to the disease. This negative correlation indicated that proximity to the

dumpsite exposed children to the hazards of malaria infection. Similarly, the correlation coefficient of 0.14 (p<0.05) in Zone B indicates that long distance from dumpsite lowers exposure to the disease. This also implies that the rate of hospitalization decreased with increasing distance from the dumpsite with a strong evidence of a spatial trend (p<0.0001). Correlations during seasonal exposures (dry and wet seasons) were 0.77 and 0.52 and positive. Results also showed a strong association between distance from the dumpsite and malaria disease in the overall sample (OR=3.2, 95%, Cl.7-7.2). The association varied among the age groupings of the children and relative distance from the dumpsite. It was strongest for the children below 3 years of age (adjusted OR=3.3, 95%, CI 1.19-8.1) than those above 4 years in Zone A (OR=2.5, 95%, CI 1.3-6.7) and those in Zone B (OR=2.7, 95%, CI 1.38-5.7). Furthermore, the effect estimate for cumulative malaria infection increased the odds of the disease for children below 3 years of age by 9.3% per inter quartile range (IQR). The overall result showed that children living within a distance of between 100 and 200 meters from the dumpsite (Zone A) are 3.5 times more likely to suffer from malaria than those living beyond 500 meters distance (Zone B). A trend of lower incidence of malaria was therefore noted among children living in Zone B, which was the less exposed zone.

The results obtained from this study suggest that children are vulnerable to environmental diseases such as malaria. They also indicate that the level of vulnerability is a function of the level of exposure and distance to the source of the disease (Anderson and May, 1982; Fasan, 1969). It was observed that the peak period of malaria infection corresponded with months of climatic transition with low rainfalls, which encouraged the breeding of anopheles mosquitoes at the dumpsite (Okogun, 2003). This corroborates Tibbetts (2007) stance that mosquitoes and the disease they carry are especially sensitive to temperature changes. In the same vane,

Tibbetts and Epstein (2005) also maintained that warm temperatures accelerate the maturation of disease-vectors such as mosquitoes as they tend to concentrate in the same places which enhance the transmission of the paraste they carry. It is known that if the plasmodium parasite is not properly killed in the human bloodstream, it might lead to the emergence of a strain that might be resistant to drugs and frequent hospitalization of the patient (William,1996; Mendis and Cater, 1995). If the drop in the rate of infection and hospitalization in June 2006 corresponded with months of high rainfall when these vectors lay their eggs in humified waste dumps, the low value of infection recorded in the month of February 2007 may be attributed to the chilling effect caused by the Harmattan wind, when all the children are properly covered against cold, which consequently protected them from frequent mosquito bites.

Other cogent reasons emerged to buttress our argument that proximity to the waste dump increased the incidence of malaria and high rate of hospitalization among children living in the study area and these include:

  1. All the parents of the subjects indicated in the questionnaire that the incidence of malaria before the appearance of the waste dump in the area was minimal.
  2. The presence of the dumpsite and the accumulation of waste provided breeding ground for mosquitoes that vehicle this disease.
  3. The exposure route was only through mosquito bites among a population group that is highly vulnerable and less mobile.

 

Overall, our results show that the growing health disparities that result from poverty and inadequate infrastructure and service provision in our urban areas raise serious concerns about environmental justice (Thomas et al, 2006; Pellow and Brulle, 2005). The high rate of hospitalization due to malaria especially

 

among the most vulnerable groups such as children, and other likely diseases arising from poor management of municipal solid waste should make this sector an obvious priority. Our results constitute an eloquent testimony that children living in low income and poor neighborhoods are often at greater risk of exposure to environment-based hazards than other groups (Tillett, 2007; Been, 1993).

 

Conclusion
This study is one of the evidences that support the argument that exposure to environmental pollutants such as waste dumps, can contribute to compromise urban public health and the pathology of related diseases (Hennig et al, 2005, Needham et al, 2005). Several risk factors for malaria were not controlled (diet, use of net and insecticides, latent period, etc.) which may appear as important confounders when their frequency in the sub-population are associated with exposures. Despite these limitations, we argue that if our results could show high rates of malaria incidence and hospitalization among our subjects when our exposure assessment is fraught with certain limitations, then it could be that the real relationships between malaria and proximity to waste dumps may likely be stronger. Nonetheless, the case study is a clear demonstration that accumulation of solid waste in proximity to residential areas constitutes a pathway to many chronic diseases including malaria. There is great need to further explore the waste-malaria paradigm in environmental health studies with the view to developing new strategies for intervention and prevention of this disease (Spivey, 2007). Ultimately, the promotion of urban cleanliness and effective management of municipal wastes may be the most sensible strategies to “Roll Back Malaria” in Nigerian urban areas in the years ahead.

References
Afolabi, B. (2006) Why Malaria is more deadly in Nigeria.

 

Pharmanews  28 (5) 1-6

Allen, S.J. (1997). Thalassemia protects children against diseases caused by other
infections as well as malaria. Proc. NAL Acad  Sc. USA. 94:14736-14741.

Anderson, R.M. and May R.M. (1982) Coevolution of hosts and parasites.
Parasitology 85:41-426

Ayala, F.J.; Escalente, A.A; Rich, S.M. (1999) Evolution of plasmodium and the
recent origin of  the World Populations of Plasmodium falciparum Parasitologia 41:55-68.

Been, V (1993) What’s fairness got to do with it? Environmental Justice and the
siting of locally undesirable land uses. Cornell Law Rev. 78:1001-1085.

Bisseru, U.B. (1985) Chloroquin resistance in Africa. Postgraduate Africa 7:58-64

Bruce-Chwatt, L.S. (1985) Essential Malariology. 2nd Ed. London. William Heinman Med
Books,

Coluzzi, M. (1999) The clay feet of the malaria grant and its African roots:
Hypothesis and Inferences about origin, spread and control of Plasmodium            falciparum. Parasitologia 41: 277-283.

Faber, D. and Krieg, E. (2001) Unequal Exposure to Ecological Hazards:
Environmental Injustices in the Commonwealth of Massachusetts: A Report by the Philanthropy and Environmental Justice Research Project. Boston: Northeastern University

Fasan P.O.  (1969) Malaria in school children of Lagos city and Lagos state.

         
 West Africa J. 18:176-180

Federal Environmental Protection Agency (1999) Report on the State of Nigerian
Environment, Abuja, Fed. Govt. Press.

Federal Ministry of Health (1989) Guidelines for Malaria Control in Africa.
Lagos Nigeria.

Gadzama, N.M. (1983) Mosquito vectors of Sahel Savannah environmental
development. Annals of Borno: 1:99-104

Gatrell, C.A. and Lovett, A.A. (1995) Burning Questions: Waste and Implications for
Human Health, Chap.9, Waste Location and Environment pp.143-157.

Goren, A. and Hellman, S. (2001) Impact of Vehicular Air Pollution on Health of
Children in Tel Aviv: Isreal Environment Bulletin,  Tel Aviv, Ministry of Environment . Winter, 2001-5761, Vol. 24 No.1.

Hemingway, J. (1999) Insecticide Resistance in Malaria Vectors: A New Approach to
an old subject. Parasitologia 41:515-518.

Henning, B. Reiterer, G. Majkova, E. et al (2005) Modification of Environment
Toxicity by Nutrients: Implications in Artherosclerosis; Cadiovasc Toxicol 5(2): 153-160.

Ikhisemoge, T. (2006) Health Encyclopedia: Diseases and Conditions; A Seminar on
New Trends of Malaria Management in Nigeria, Pharmanews, Oct. 2006.

Jacquiet, D. (2001) The role of rapid diagnostic test in malaria diagnosis.
J. African Health 8:7-9.

Katsouyanni, K., Touloumi, G., Samoli, E., Gryparis, A., Monopolis, Y. and Le Tertre,

A., (2001) Confounding and effect modification in the short-term of ambient particles on total mortality: Results from 29 European cities within APHEA 2 Project Epidermiology 12 (2) 521 -531. 

Khitotiya, R.K.(2004) Environmental Pollutions: Management and Control
           Sustainable Development. New Delhi S. Chad and Company Ltd. Chap.4 

Mendis, K.N. and Carter R. (1995) Clinical Diseases and Pathogenesis in Malaria
Parasitology Today 11(5) 101-110.

Needham, L.L.; Barr. D.B., Caudill, S.P. (2005) Concentration of Environmental
Chemicals Associated with Neuro-development Effects in US Population Neuroloxicology, 26(4):531-545.

Okogun, G.A.R. (2003) Ecology; Biology of Anopheles mosquitoes and prevalence
transmission intensity of malaria in mid-West Nigeria. Doctoral Dessartation in Med. Parasitology. Imo State Uni, Owerri 272p

 

Peace, T. and Mazumder, A. (2007) Tracking Patterns of Enteric Illnesses in
Populations and Communities; Environmental Health Perspectives
115,(1):58-64.

Pellow, D. N; Brulle and R.J. (2005) Power, Justice and The Environment: A
Critical Appraisal of the Environmental Justice Movement, Cambridge, MA; MIT Press.

Pezzoli, K. and Turkey R.(2007) The NIEHS Environmental Health Sciences Data
Resource Portal: Placing Advance Technology in Service of Vulnerable Communities; Environmental Health Perspective115, (4):564-571.

Sheldon, T.A. and Smith D. (1995) Assessing the Health Effects of Disposal Sites:
Issues in Risk Analysis and Some Bayesian Conclusions. Chap. 10. Waste Location and Environment. pp.158-186.

Snow, R.W. (1997) Relation between severe malaria morbidity in children and level
of Plasmodium falciparum transmission in Africa. Lancet 349:1650-1654.

Spivey, A. (2007) Children’s Health Centres; Past, Present and Future.
In: Environmental Health Perspectives115(4): A 192-194.

Sturchler, D. (1989) How much malaria is there worldwide
Parasitology Today 5:39-40

Swan, J.R.M., Crook, B.; Gilbert, J. (2002) Microbial Emissions from composting sites. In: Environmental and Health Impact of Solid Waste Management Activities (eds Hester R E and Harrison R M). Issues in Environmental Science and Technology, Vol.18:73-101 Cambridge, R.S. of Chemistry.

Thomas, G.E; Mitchell, F. and Williams, M.eds (2006) Examining the Health Disparities Research Plan of the National Institute of Health;

Unfinished Business, Washington. D.C., NAP.

Tibbett, J. (2007) Health Effects on Climate Change. In: Environmental Health Perspectives 115(40):197-203.

Tibett, J. and Epsein, E. eds (2005) Climate Change Futures: Health, Ecological and Economic Dimensions, WHO Pub, New York, 2005.

Tillett, T. (2007) “Healthy Home, Healthy Community. In: Environmental Health Perspectives 115 (4):194-195.

Tonne, C., Melly, S., Muttleman, M., Coull, B. Goldbery, R. and Schwartz, J. (2007).
A case control Analysis of Exposure to traffic and myocardial Infarction
            Environ Health Perspect 115(1): 53-57.

Tony, G.O. (1978) The breeding site preference of mosquitoes in Ibadan, Nigeria.
            Nigeria J. Entomol 1 (3):71-75.

William, T.N. (1996) High Incidence of Malaria in Thalasemia Children
J. Nature 383:522-525

 

Young, O.R, and Berkout F.(2006) The Globalization Systems: An Agenda for
Scientific Research, GlobEnviron Change 16:304-316.