SEGH Articles

# Putting the Health in SEGH

18 November 2015
Dr Alex Stewart, recently retired from Public Health England, has been an active member of the SEGH International board over many years and a major driving force in bringing the health community together with environmental scientists to promote inter-disciplinary research.

Dr Alex Stewart retired at the end of June as a Consultant in Health Protection for Public Health England, for which his responsibilities included the recognition, characterisation and response to the health effects of environmental issues, including the geochemical components.  Dr Stewart has been involved in SEGH activities for about 20 years, having gained experience and an interest in linking environmental geochemistry and its influence on human health through his interest in iodine deficiency in his years as a GP in the Karakoram mountains of northern Pakistan.

We take the opportunity to ask a few questions of Alex to gain an insight into his extensive experience to the benefit of other scientists at any stage of their career.  In addition, Alex gives us some idea of his plans for the future and his continued engagement with SEGH.

When you started out on your career, what were your fears, hopes, and the reality?  Were there any surprises along the way?

As a young medical doctor I wanted to work in the wilder parts of the world, but wondered if I was up to it. I was able to join an experienced doctor in starting the General Practice in Baltistan, northern Pakistan, where the health services were thin, stretched and of limited ability. When my colleague retired a few years later, I took over with confidence and developed the work. Perhaps the biggest surprise was my ability to adapt good medical practice in a situation where resources were limited (we ran an outpatient clinic without nearby hospital or laboratory support) and the villagers did not always return quickly for review. It was sometimes hard to know if patients had died, got better or decided my treatments were not worth having! This made learning about what worked and what did not a lot slower but eventually earned me local respect because I was able to ground the medical work in a deep knowledge of the local community.

How were the environmental and health sciences considered early in your career and was there much collaboration between disciplines at the time?

We in health had little understanding of the impact of environmental issues on health, particularly when I was a student and young doctor. Doctors still largely concentrate on the person sitting in our consulting room and ignore wider issues, including, sadly, family and social aspects. The natural environment hardly came into my early understanding of health and disease.

Was there any one event that stood out for yourself personally that influenced your career or the perception of geochemical and health research?

The sharpest event that affected my perception of geochemistry and health was an evening in our house in Baltistan with two passing geologists from Oxford. They were studying the Main Karakoram Thrust, often by binoculars from their jeep in the valley, covering a lot of ground quickly: Baltistan is dry, with very little soil cover on the rocks, so the basic geology can be quite clear in many places. I had become interested in the locally perceived differences in the prevalence of goitre (thyroid swelling in the neck due, in this area, to iodine deficiency) between our side of the river (“1/100”, I was told) and the inhabitants of the villages across the river (“1/10” was the local comment). I had looked and asked about differences between the two sides of the valley and could find nothing that made sense until these passing geologists showed me the Main Karakoram Thrust and indicated its importance as the boundary between Asia (the far side) and the Island Arc north of India (our side). As I began to look into this it was clear that plate tectonics played some part in the distribution of the iodine deficiency disorders across northern Pakistan and perhaps further afield (Stewart AG. Drifting continents and endemic goitre in northern Pakistan. British Medical Journal, 1990; 300: 1507-1512). Following this through led eventually to my appointment as a Consultant in Health Protection with interest in and responsibility for environmental issues (e.g. Mahoney G, Stewart AG, Kennedy N, Whitely B, Turner L, Wilkinson E. Achieving attainable outcomes from good science in an untidy world: Case studies in land and air pollution. Environmental Geochemistry & Health. 2015; 37: 689-706.).

SEGH has been of enormous support, stimulation and help in my career over the past 20-odd years. I first encountered it at a halogen meeting in Kingston-upon-Thames while home on leave in 1994. I went to hear Ron Fuge, the iodine guru from Aberystwyth. Although Ron was unable to attend the meeting at the last minute, I found some of the other presentations fascinating and Joy Carter (former SEGH President), at Reading in those days, enrolled me into SEGH. This encouraged me (particularly after our sudden and unexpected return to the UK in 1996 after the Pakistani Government asked us to leave, reasons unstated) to build friendships, read the journal, and attend meetings. Through the SEGH meetings, in particular, I met a lot of fascinating people and learned a lot more than I could have imagined about the environment, geochemistry and possible influences on health. I also gave presentations or posters which were probed in the SEGH gentle but knowledgeable manner, helping develop my thinking on a number of issues. I have been delighted to serve on the SEGH board; SEGH has been a constant during periods of diminished support for environmental public health issues in the health protection arena (Stewart AG, Worsley A, Holden V, Hursthouse AS. Evaluating the impact of interdisciplinary networking in Environmental Geochemistry and Health: Reviewing SEGH conferences and workshops. Environmental Geochemistry and Health, Special edition. 2012; 34(6): 653-664).

Do you have any advice for young scientists setting out on their careers in environmental geochemistry or health sciences?

Don’t be afraid of cross-boundary work: that’s where exciting challenges and discoveries are to be made in any subject. Develop friendships and relationships with people outside your speciality, learn their scientific language and ways of thinking and undertake joint work. You never know where that will lead.

What do you consider to be the important topics for environmental-geochemistry-health related research in the future?

We need to continue our interest in elemental chemistry, but move beyond metals into organics, into volatiles, building relationships with air-scientists to look at the unseen pollution and health effects of fine and ultra-fine particles. I think linking the genetic fingerprint of cancers with specific toxins will enable us to identify, control and reduce/prevent specific diseases. However, this cannot be done by either geochemists or health professionals alone, but only in collaboration. Collaboration means both sides actively being involved in each other’s research proposals and activities, not just bolting two different approaches together.

What are some of your hopes for the future?

I would dearly like to see more health professionals involved with SEGH, but have run out of ideas how to involve them. I hope the younger generation of scientists can succeed where I have been unsuccessful.

Now that I am retired I hope to have some time to examine some of the environmental-health questions that have sat on my desk for 10+ years, such as: Does environmental iodine deficiency exist? What is the explanation for the global distribution of iodine deficiency disorders? What is the environmental input, if any, into lung cancer in North West England? Could some of the ill-health of deprived communities in industrialised countries be due to historical pollution, perhaps through trans-generational mechanisms?

On a personal note, Alex has made an important contribution to SEGH's encouragement of cross disciplinary work across geochemistry and health sciences, both in the UK and through European meetings.  Alex's tireless enthusiasm has helped to provide a platform from which the following generation of cross disciplinary scientists are less inhibited by the artificial boundaries.  Fortunately, Alex will continue to be engaged with SEGH, clearly with some exciting issues to pursue in retirement.

by Dr Michael Watts

British Geological Survey (SEGH webmaster)

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.