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

## SEGH 34th International Conference on Sustainable Geochemistry

Victoria Falls, Zimbabwe

02 July 2018

## SubmitContent

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

## Science in theNews

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

• Characteristics of PM 2.5 , CO 2 and particle-number concentration in mass transit railway carriages in Hong Kong 2017-08-01

### Abstract

Fine particulate matter (PM2.5) levels, carbon dioxide (CO2) levels and particle-number concentrations (PNC) were monitored in train carriages on seven routes of the mass transit railway in Hong Kong between March and May 2014, using real-time monitoring instruments. The 8-h average PM2.5 levels in carriages on the seven routes ranged from 24.1 to 49.8 µg/m3, higher than levels in Finland and similar to those in New York, and in most cases exceeding the standard set by the World Health Organisation (25 µg/m3). The CO2 concentration ranged from 714 to 1801 ppm on four of the routes, generally exceeding indoor air quality guidelines (1000 ppm over 8 h) and reaching levels as high as those in Beijing. PNC ranged from 1506 to 11,570 particles/cm3, lower than readings in Sydney and higher than readings in Taipei. Correlation analysis indicated that the number of passengers in a given carriage did not affect the PM2.5 concentration or PNC in the carriage. However, a significant positive correlation (p < 0.001, R 2 = 0.834) was observed between passenger numbers and CO2 levels, with each passenger contributing approximately 7.7–9.8 ppm of CO2. The real-time measurements of PM2.5 and PNC varied considerably, rising when carriage doors opened on arrival at a station and when passengers inside the carriage were more active. This suggests that air pollutants outside the train and passenger movements may contribute to PM2.5 levels and PNC. Assessment of the risk associated with PM2.5 exposure revealed that children are most severely affected by PM2.5 pollution, followed in order by juveniles, adults and the elderly. In addition, females were found to be more vulnerable to PM2.5 pollution than males (p < 0.001), and different subway lines were associated with different levels of risk.

• Comparison of chemical compositions in air particulate matter during summer and winter in Beijing, China 2017-08-01

### Abstract

The development of industry in Beijing, the capital of China, particularly in last decades, has caused severe environmental pollution including particulate matter (PM), dust–haze, and photochemical smog, which has already caused considerable harm to local ecological environment. Thus, in this study, air particle samples were continuously collected in August and December, 2014. And elements (Si, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Mo, Cd, Ba, Pb and Ti) and ions ( $${\text{NO}}_{3}^{-}$$ , $${\text{SO}}_{4}^{2-}$$ , F, Cl, Na+, K+, Mg2+, Ca2+ and $${\text{NH}}_{4}^{+}$$ ) were analyzed by inductively coupled plasma mass spectrometer and ion chromatography. According to seasonal changes, discuss the various pollution situations in order to find possible particulate matter sources and then propose appropriate control strategies to local government. The results indicated serious PM and metallic pollution in some sampling days, especially in December. Chemical Mass Balance model revealed central heating activities, road dust and vehicles contribute as main sources, account for 5.84–32.05 % differently to the summer and winter air pollution in 2014.

• Annual ambient atmospheric mercury speciation measurement from Longjing, a rural site in Taiwan 2017-08-01

### Abstract

The main purpose of this study was to monitor ambient air particulates and mercury species [RGM, Hg(p), GEM and total mercury] concentrations and dry depositions over rural area at Longjing in central Taiwan during October 2014 to September 2015. In addition, passive air sampler and knife-edge surrogate surface samplers were used to collect the ambient air mercury species concentrations and dry depositions, respectively, in this study. Moreover, direct mercury analyzer was directly used to detect the mercury Hg(p) and RGM concentrations. The result indicated that: (1) The average highest RGM, Hg(p), GEM and total mercury concentrations, and dry depositions were observed in January, prevailing dust storm occurred in winter season was the possible major reason responsible for the above findings. (2) The highest average RGM, Hg(p), GEM and total mercury concentrations, dry depositions and velocities were occurred in winter. This is because that China is the largest atmospheric mercury (Hg) emitter in the world. Its Hg emissions and environmental impacts need to be evaluated. (3) The results indicated that the total mercury ratios of Kaohsiung to that of this study were 5.61. This is because that Kaohsiung has the largest industry density (~60 %) in Taiwan. (4) the USA showed average lower mercury species concentrations when compared to those of the other world countries. The average ratios of China/USA values were 89, 76 and 160 for total mercury, RGM and Hg(p), respectively, during the years of 2000–2012.