SEGH Articles

Is there an environmental link to esophageal cancer in Tanzania?

07 July 2015
Scientists from the Centre for Environmental Geochemistry are helping health organisations understand why esophageal cancer is localised within specific areas of the African Rift Valley. Whilst various causal factors are now under investigation, such as high-strength kill-me-quick alcohol consumption or hot tea drinking, it is difficult to fully explain the localised nature of the burden. Here Dr Michael Watts outlines why soil around Mount Kilimanjaro could unearth some answers.

Dr Valerie McCormack from the International Agency for Research on Cancer (IARC, part of the World Health Organisation) has studied the high prevalence of esophageal cancer in the Rift Valley and identified a particularly localised incidence of cases in the Mount Kilimanjaro area of Tanzania. A hypothesis was presented that an environmental factor, such as exposure to potentially harmful elements or organics (e.g. polycyclic aromatic hydrocarbons, PAHs, from wood fires) or deficiency of essential micronutrients (e.g. zinc) that diminishes the body’s ability to recover from or buffer an event that may cause cell damage, could be contributing to this.

Kilimanjaro District

This is where the skills of the Centre for Environmental Geochemistry (CEG) team come in. The BGS Inorganic Geochemistry team assisted IARC-WHO and the Kilimanjaro Christian Medical Centre (KCMC) in designing and undertaking a detailed survey of soil, water and crop samples in the Kilimanjaro district.

Children in Masame

Our primary aim was to link geochemistry and crop data with areas in which esophageal cancer cases were prevalent.  In addition, the data will demonstrate a spatial understanding of the geochemistry of the differing climatic zones and food production areas around Mount Kilimanjaro and to provide an indication of micronutrient composition or presence of potentially harmful elements.

Masame

This increased understanding of the soil and crops in Kilimanjaro will improve baseline evidence for a differing climatic zone compared to previous work in Sub-Saharan Africa (previous blogs), to inform future experimentation of agricultural methods that could improve soil-crop transfer of micronutrients for onward health benefits. 

Kilimanjaro

We also provided training to local counterparts from KCMC and the Ministry of Agriculture Kilimanjaro District Extension Office in the collection of environmental samples, recording of field data for quality assurance / data management and onward presentation in GIS maps for agricultural planning tools. It is a privilege to be able to help where our skills are needed most and it’s clear these strong working relationships will bring benefits to local populations and the wider science community. We see clear opportunities for future collaboration with all of the partners we worked with in Tanzania, including the Regional Area Secretariat from the Prime Minister’s Office.

Rombo Mkuu

In fact the CEG has already partnered again with IARC-WHO (the project leaders) on a recently gained grant from the US National Cancer Institute to study a similarly high-localised prevalence of esophageal cancer in the Eldoret region of Kenya.  Such work involves the cross-disciplinary collaboration of epidemiologists, medics, health practitioners, biostatisticians, geochemists, farmers and local agricultural extension workers and commences 2015 to 2017. Watch out for future blogs and see all our research via our CEG website - www.environmentalgeochemistry.org. 

Dr Michael Watts
Head of Inorganic Geochemistry, Centre for Environmental Geochemistry


Suggestions for further reading:

Joy et al. (2015). Zinc enriched fertilisers as a potential public health intervention in Africa, DOI:10.1007/s11104-015-2430-8. 

Gibson RS, Wawer AA, Fairweather-Tait SJ, Hurst R, Young SD, Broadley MR, Chilimba ADC, Ander EL, Watts MJ, Kalimbira A, Bailey KB, Siyame EWP. (2015). Dietary iron intakes based on food composition data may underestimate the contribution of potentially exchangeable contaminant iron from soil, Journal of Analytical Food Research (in press).

Joy, EJM, Broadley, MR, Young, SD, Black CR, Chilimba, ADC, Ander, EL, Barlow, TS and Watts, MJ*. (2015). Soil type influences crop mineral composition in Malawi, Science Total Environment, 505, 587-595.

Joy, E, Ander, EL, Young, SD, Black, C, Watts, MJ, Chilimba, ADC, Chilima, B, Siyame, E, Kalimbira, A, Hurst, R, Fairweather-Tait, SJ, Stein, A, Gibson, RS, White, P, Broadley, M. (2014) Dietary mineral supplies in Africa, Physiologia Plantarum, 151, 208-229.

Siyame E; Hurst R; Wawer AW;Young SD; Broadley MR; Chilimba ADC Ander EL; Watts MJ; Chilima B; Gondwe J; Kang’ombe D; Kalimbira A; Fairweather-Tait SJ; Bailey KB; Gibson RS. (2014). A high prevalence of zinc but not iron deficiency among Women in Rural Malawi: a cross-sectional study, International Journal for Vitamin and Nutrition Research, 83, 3, 176-187.

Hurst, R, Siyame, E, Young, SD, Chilimba, ADC, Joy, EJM, Black, CR, Ander, EL, Watts, MJ, Chilima, B, Gondwe, J, Kang’ombe, D, Stein, AJ, Fairweather-Tait, SJ, Gibson, R, Kalimbira, A, Broadley, MR*. (2013). Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi, Scientific Reports, 3, 1425.

Broadley MR, Chilimba ADC, Joy, E, Young SD, Black CR, Ander EL, Watts MJ, Hurst R, Fairweather-Tait SJ, White PJ, Gibson RS. (2012). Dietary requirements for magnesium but not calcium are likely to be met in Malawi based on national food supply data, International Journal of Vitamin and Nutrition Research, 82(3), 192-199.

Joy EJM, Young SD, Black CR, Ander EL, Watts MJ and Broadley MR. (2012). Risk of dietary magnesium deficiency is low in most African countries based on food supply data, Plant and Soil, 368. 129-137.

W H Shetaya, S D Young, M J Watts, E L Ander and E H Bailey (2012). Iodine dynamics in soils, Geochemica et Cosmochimica Acta, 77, 457 – 473.
Chilimba, A.D.C., Young, S.D., Black, C.R., Ander, E.L., Watts, M.J., Lammel, J. and 

Broadley, M.R. (2011). Maize grain and soil surveys reveal suboptimal dietary selenium intake is widespread in Malawi, Scientific Reports, 1, 1 - 9.


 

 

Keep up to date

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • The society for environmental Geochemistry and health (SEGH): a retrospect 2019-02-22
  • Air quality and PM 10 -associated poly-aromatic hydrocarbons around the railway traffic area: statistical and air mass trajectory approaches 2019-02-19

    Abstract

    Diesel engine railway traffic causes atmosphere pollution due to the exhaust emission which may be harmful to the passengers as well as workers. In this study, the air quality and PM10 concentrations were evaluated around a railway station in Northeast India where trains are operated with diesel engines. The gaseous pollutant (e.g. SO2, NO2, and NH3) was collected and measured by using ultraviolet–visible spectroscopy. The advanced level characterizations of the PM10 samples were carried out by using ion chromatography, Fourier-transform infrared, X-ray diffraction, inductively coupled plasma optical emission spectrometry , X-ray photoelectron spectroscopy, field-emission scanning electron microscopy with energy-dispersive spectroscopy, and high-resolution transmission electron microscopy with energy-dispersive spectroscopy techniques to know their possible environmental contaminants. High-performance liquid chromatography technique was used to determine the concentration of polycyclic aromatic hydrocarbons to estimate the possible atmospheric pollution level caused by the rail traffic in the enclosure. The average PM10 concentration was found to be 262.11 µg m−3 (maximum 24 hour) which indicates poor air quality (AQI category) around the rail traffic. The statistical and air mass trajectory analysis was also done to know their mutual correlation and source apportionment. This study will modify traditional studies where only models are used to simulate the origins.

  • The geochemistry of geophagic material consumed in Onangama Village, Northern Namibia: a potential health hazard for pregnant women in the area 2019-02-18

    Abstract

    Ingestion of geophagic materials might affect human health and induce diseases by different ways. The purpose of this study is to determine the geochemical composition of geophagic material consumed especially by pregnant women in Onangama Village, Northern Namibia and to assess its possible health effects. X-ray fluorescence and inductively coupled plasma mass spectrometry were used in order to determine the major, and trace elements as well as anions concentrations of the consumed material. The geochemical analysis revealed high concentrations of aluminium (Al), calcium (Ca), iron (Fe), magnesium (Mg), manganese (Mn), potassium (K), sodium (Na), and silica (Si); and trace elements including arsenic (As), chromium (Cr), mercury (Hg), nickel (Ni) and vanadium (V) as well as sulphate (SO42−), nitrate (NO3), and nitrite (NO2) anions comparing to the recommended daily allowance for pregnant women. The pH for some of the studied samples is alkaline, which might increase the gastrointestinal tract pH (pH < 2) and cause a decrease in the bioavailability of elements. The calculated health risk index (HRI > 1) revealed that Al and Mn might be a potential risk for human consumption. Based on the results obtained from the geochemical analysis, the consumption of the studied material might present a potential health risk to pregnant women including concomitant detrimental maternal and foetal effects.