Alex G. Stewart

Osteomalacia in Hazara District, Pakistan

Osteomalacia is most commonly seen in the remoter northern regions (Kohistan District) of Hazara District, Pakistan. Low serum calcium is common, as is tetany, but not universal. A 2% prevalence was found retrospectively in all obstetric patients from 1978-1985. Overall, there was a 12% caesarean section rate (61/annum), of which 37% (22) exhibited cranio-pelvic disproportion, nearly half of which (n=83, 46%) were thought clinically to be due to osteomalacia. Osteomalacia was found prospectively in 3.6% of all female outpatients (3600/100,000). Purdah did not appear to influence the incidence of osteomalacia, although sunlight exposure varied significantly due to place of abode (0.05 >P > 0.025); those living in the deeper, darker valleys suffered more from osteomalacia and its side effects, such as cranio-pelvic disproportion and the resulting need for caesarean sections. Diet is an important factor, showing little variety in the affected region; it lacks animal protein and is low in calories. The estimated intake of vitamin D is ~1 μg per day, seriously short of the daily requirement of 2.5 μg. The other main factor is higher parity in the women with osteomalacia (15/18 affected women had more than three pregnancies compared with 9/18 controls; odds ratio 13, 0.05 > P > 0.025). These all indicate that in a marginal situation added metabolic stress can precipitate the condition. While supplementation of the diet is essential in such communities it will be difficult to initiate and maintain. We therefore also recommend that strategies for prevention be focused on the men to encourage them to help improve the diet and lifestyle of their womenfolk.

Real or illusory? Case studies on the public perception of environmental health risks in the north west of England.

Applied research in a public health setting seeks to provide professionals with insights and knowledge into complex environmental issues to guide actions that reduce inequalities and improve health. We describe ten environmental case studies that explore the public perception of health risk. We employed logical analysis of components of each case study and comparative information to generate new evidence. The findings highlight how concerns about environmental issues measurably affect people’s wellbeing and led to the development of new understanding about the benefits of taking an earlier and more inclusive approach to risk communication that can now be tested further.

The illusion of environmental iodine deficiency.

The distribution of endemic goitre in England and Wales was compared with the distribution of environmental iodine (atmospheric deposition, soil, surface water). Despite a very clear goitre belt through the west of England and Wales there was no patterning in the environmental iodine distribution. A clear seasonal variation in depositional iodine exists, with an unusually high concentration of iodine in March 1997. The temporal variation in iodine concentration is determined at the monthly and not the annual level. The presence of endemic goitre is no indicator of how iodine is distributed in the environment or vice versa!

Clinical and epidemiological correlates of iodine deficiency disorders

Abstract The iodine deficiency disorders, endemic goitre, stillbirths, abortions, congenital abnormalities, endemic cretinism, and impaired mental function, are found worldwide. Known for millenia, they currently put 29% of the world’s population at risk. The most important is cretinism, found in two forms. Neurological cretinism possibly develops due to an insult in early pregnancy, hypothyroid cretinism to an insult late in pregnancy or in early life. The classical medical causes of environmental iodine deficiency, glaciation and leaching, do not adequately explain the prevalence and distribution of iodine deficiency disorders, nor have the new insights into the environmental chemistry of iodine been assimilated properly with medical knowledge. Joint studies would be of help. The presence of various factors other than iodine deficiency in the causation of the disorders is recognized. These are often thought to be geologically related. Recent work suggests plate tectonics as the unifying factor, since iodine deficiency disorders are found along many plate collision zones. Concentration of major and trace elements as a result of plate subduction provides a possible source of goitrogens. A systematic search is needed. The iodine goitrogen ratio could provide the link between environmental iodine and differing intensities of the iodine deficiency disorders found in affected communities.

Drifting continents and endemic goitre in northern Pakistan.

Although Baltistan, north east Pakistan, is in a region of iodine deficiency disorders, the distribution of goitre within the district, according to age and sex, has not been clearly defined. To establish the prevalence of the condition and to measure the reported difference in prevalence in the north and south of the district thyroid size was assessed in new patients attending the Aman clinic, Khapalu, and outlying areas between April and September from 1981 to 1986. Samples of potable water collected from villages were analysed for iodine (as iodide) concentrations in Britain. Population weighted prevalences were: in the north in males 20.4%, in females 28.1% and in the south in males 13.9%, in females 21.2%. There was an overall deficiency of iodine in the water (mean iodine (as iodide) concentrations (north) 11.0 nmol/l (1.4 micrograms/l), (south) 11.8 nmol/l (1.5 micrograms/l) (95% confidence interval -0.7 to 0.9). The differences followed the Main Karakoram Thrust, suggesting a geological goitrogen in the north, which might be minerals containing ions such as BF4- and SO3F-, and molybdenite and calcium, which are present in rocks in Baltistan. A new hypothesis for the genesis of endemic goitre is proposed--that is, that continents on crustal plates drift across the earth and collide, one plate sliding under the other and melting, giving rise to characteristic mineral assemblages in the overlying rocks. As the minerals weather out they enter the diet of the local population, where in the presence of iodine deficiency they produce or enhance iodine deficiency disorders. Despite the current iodised oil campaign by the Pakistani government with Unicef a long term working iodisation programme is still urgently needed.

Towards the development of a multidisciplinary understanding of the effects of toxic chemical mixtures on health

Mixtures can be divided into simple (chemicals with comparable properties—health risk assessments on the chemicals) and complex, which can be further subdivided into defined (a reasonably distinct composition, created at a specific time and place despite dissimilar components—risk assessments on the common source) and coincidental (chemicals without similar properties or constant composition in time or space—risk assessments on the receptor). Interactions recognized are: independent action, dose addition (additivity), and potentiation (synergy and antagonism). Unpredicted outcomes need recognition. New approaches in higher education and multidisciplinary investigations are essential. The community of the Society for Environmental Geochemistry and Health should help clarify points such as when transformations in mixtures may become important enough to alter the classification and the risk assessment. The multidisciplinary community is also well placed to support the integration of nonchemical influences into mixture analysis and to contribute to the investigation of cumulative and multiple exposures.

Achieving attainable outcomes from good science in an untidy world: case studies in land and air pollution

While scientific understanding of environmental issues develops through careful observation, experiment and modelling, the application of such advances in the day to day world is much less clean and tidy. Merseyside in northwest England has an industrial heritage from the earliest days of the industrial revolution. Indeed, the chemical industry was borne here. Land contamination issues are rife, as are problems with air quality. Through the examination of one case study for each topic, the practicalities of applied science are explored. An integrated, multidisciplinary response to pollution needs more than a scientific risk assessment. The needs of the various groups (from public to government) involved in the situations must be considered, as well as wider, relevant contexts (from history to European legislation), before a truly integrated response can be generated. However, no such situation exists in isolation and the introduction of environmental investigations and the exploration of suitable, integrated responses will alter the situation in unexpected ways, which must be considered carefully and incorporated in a rolling fashion to enable solutions to continue to be applicable and relevant to the problem being faced. This integrated approach has been tested over many years in Merseyside and found to be a robust approach to ever-changing problems that are well described by the management term, “wicked problems”.

Spatial analysis of health effects of large industrial incinerators in England, 1998-2008: a study using matched case-control areas.

Objectives To assess whether residential proximity to industrial incinerators in England is associated with increased risk of cancer incidence and mortality. Design Retrospective study using matched case–control areas. Setting Five circular regions of radius 10 km near industrial incinerators in England (case regions) and five matched control regions, 1998–2008. Participants All cases of diseases of interest within the circular areas. Primary and secondary outcome measures Counts of childhood cancer incidence (<15 years); childhood leukaemia incidence (<15 years); leukaemia incidence; liver cancer incidence; lung cancer incidence; non-Hodgkins lymphoma incidence; all-cause mortality; infant mortality (<1 year) and liver cancer mortality. Results The estimated relative risks for case circles versus control circles for the nine outcomes considered range from 0.94 to 1.14, and show neither elevated risk in case circles compared to control areas nor elevated risk with proximity to incinerators within case circles. Conclusions This study applies statistical methods for analysing spatially referenced health outcome data in regions with a hypothesised exposure relative to matched regions with no such exposure. There is no evidence of elevated risk of cancer incidence or mortality in the vicinity of large industrial incinerators in England.

Multiple links towards integrating teams for understanding of disease and environment (MULTITUDE)

Geochemists have made important contributions in understanding the cause of environmentally related diseases such as the iodine-deficiency disorders (Fuge and Johnson 1986), fluorine toxicity (Ozsvath 2008), and natural arsenic poisoning (Smedley and Kinniburgh 2005). Similarly, the Society for Environmental Geochemistry and Health (SEGH) has developed a model to describe the relationship between lead in dust and soil and lead in blood (Wixson and Davies 1994), which has played an important part in the development of soil-guideline values in the UK and elsewhere. Nevertheless, with the continuing and rapid increase in the volume of knowledge relevant to this field, academic disciplines and areas of interests have necessarily become increasingly specialized. The resulting compartmentation has led, too often, to some disciplines inhabiting different ‘universes’ from others with whom meaningful dialogue and collaboration would be of mutual benefit, even in the environmental health field (Stewart and Pharoah 1996). Concepts, mechanisms, processes, and analytical approaches often cross disciplinary boundaries. The integration of disparate disciplines to examine subject matter from several distinct angles can be frustrating, with different vocabulary and assumptions. However, this integration is an ongoing necessity in order to develop a deeper understanding of the relevant science and to identify fresh multidisciplinary approaches to these complex issues. This special issue, which contributes towards this integration, contains six papers derived from a workshop held in June 2007 in Liverpool, UK. The general theme was the environment and human health, with a particular focus on building research capacity by forging Multiple Links Towards Integrating Teams for Understanding of Disease and Environment (MULTITUDE). The papers should be read as a whole, since the discussions within the targeted workshops crossed not only disciplinary boundaries but also fertilized each other. As a result, it became clear to both the participants and the authors that in environmental geochemistry and health, the understanding of uncertainty, both from sampling and measurement (Ramsey 2008) and conceptual (Briggs et al. 2008), is essential for the development of realistic toxicological and exposure data (Hursthouse and Kowalczyk 2008; Ramsey 2008). This in turn will enable the development of successful strategies for the reduction in the effects of contaminants on human health (Farmer and Jarvis 2008). A. G. Stewart (&) Cheshire and Merseyside Health Protection Unit, Microbiology Laboratory, Countess of Chester Health Park, London Road, Chester CH2 1UL, UK e-mail: alex.stewart@hpa.org.uk

HEALTH: A NECESSITY FOR SUSTAINABLE DEVELOPMENT

Health and sustainable development are mutually dependent: neither is possible without the other. Health is determined by many factors: hereditary; life-style; the level of education; work; the social community; the effects of the natural environment. The greatest health-related threat to sustainable development comes from infections (diarrhoea, respiratory infections, AIDS, tuberculosis and childhood infections and malaria) and psychiatric disorders, particularly depression, but including schizophrenia (madness). Infection and psychiatric disorders are given too little importance in the Johannesburg declaration. Development is not without problems that affect health: increased population stressing the food supplies; changing disease patterns; the marginalisation of vulnerable groups who tend to have poorer health, nutrition, education, access to help or little control of their circumstances; corruption; unjust trade and other economic decisions; inappropriate education and international aid; bias towards the provision of health services while ignoring the factors affecting health; unthinking introduction of western beliefs and practices; traffic fumes and accidents; and industrial and domestic pollution. Many of these problems are tackled in the declaration in some measure, but the declaration is unbalanced in its approach, focussing on minor issues to the detriment of important health matters. However, the processes to change in both health and development are the same and operate across society. Achieving sustainable development and improving health at the same time is attainable, but may take a major investment by the developing countries. The Western nations cannot be relied upon to contribute wisely and unselfishly to health and development in the rest of the world.