Readers' Forum

- it is no longer difficult to obtain an Zhijing County is one of the most severely appointment. endemic areas in Guizhou Province. A series of samples of rock, coal, soil, food, drinking­ These personal experiences and views are not water and air were taken from all the 102 vil­ intended as a criticism of the health care sys­ lages and towns in Zhijing County, covering a tem in Germany either before or after reunifi­ population of 720 000 over a total area of cation, and obviously no generalizations can 2907 sq. km. Compared with recommended be drawn from so small a sample. In addition, standard values, fluoride levels in the soil, coal the situation no doubt differs greatly in rural and air were significantly higher, as were locations. However, my involvement with the those in corn that had been smoked or stored primary health care concept leads me to in houses for more than two months. It was worry that perhaps overuse is made of tech­ clear that a relationship existed between fluo­ nology and treatment in areas where access is ride levels in coal, air and food, because no obstacle. There is certainly room in the freshly harvested crops were found to contain existing health system for a more effective much less fluoride. combination of disease prevention, continuity of care, and holistic approaches. Investigations revealed that the villagers habit­ ually burned coal in an uncovered and chim­ Walter Hubrich ney-less stove to smoke and dry the harvested Oberonstrasse 14 E, crops, especially corn, in order to prevent mil­ 01259 Dresden, Germany dew or rotting. In addition, coal was burned for domestic heating and cooking. Smoked corn accounted for about 70% of food Endemic fluorosis in Guizhou Province, China consumed in the area. Mean daily intake of fluoride was determined as about 10 mg per Sir - The high prevalence of endemic fluorosis person, of which approximately 90% orig­ in Guizhou Province is similar to that in other inated from the pollution of food during southern provinces of China such as Hunan, smoking and drying. Sichun and Yunnan. It is caused mainly by consuming food that has been polluted by the Tests were performed to simulate the tradi­ burning of domestic coal, rather than by tional village method of preserving corn. drinking water with a high fluoride content as Locally mined coal, containing almost 546 mg is found in most of the northern provinces. of fluoride per kg, was burned to smoke freshly harvested corn containing 0.25-0.52 mg In Guizhou Province, an area of 170000 sq. fluoride/kg. As the moisture content of the km with a population of about 32 million, corn dropped from about 47% to 11 %, endemic fluorosis is prevalent in 36 of the its fluoride content rose to 15 mg/kg after 72 counties, chiefly in the north-west. Fifteen 60 days and 35 mg/kg after 90 days. These counties have been classified as severely studies confirmed the fluoride pollution of affected and 21 as mildly affected. Dental food through coal burning as potentially the fluorosis was observed in more than 800000 main cause of endemic fluorosis in Guizhou persons. The occurrence of skeletal fluorosis Province. However, inhalation of airborne was also high (78%): most of the patients fluoride within the home may also make a complained of stiffness of main joints and significant contribution to prevalence of the limitation of movement, and bone deformities disease. were frequent.

World Health Forum • Volume 17 • 1996 173 Readers' Forum

The most effective way to control this type of because the health of populations is mostly endemic fluorosis is to eliminate or at least defined by the negative approach. For decrease open-fire coal burning in houses, by example, as pointed out by Copplestone, use of a stove with a lid and a chimney. This "mental health" statistics relate to the preva­ measure was implemented in 30% of preva­ lence or incidence of mental diseases and lent areas in Guizhou in 1982, with impressive "dental health" is often measured in terms of results: younger inhabitants showed reduced decayed, missing, or filled teeth. fluorosis levels, and children born eight years later were much less likely to develop dental It is therefore a complicated, as well as dif­ fluorosis. However, most of the stoves of rec­ ficult, task to evaluate "health" without ommended type are not properly used and negative criteria. In population studies an maintained, and 85% of stoves still need to be attempt has been made to improve the use of improved. Lack of finance and a shortage of negative criteria by discriminating between trained professional personnel are the main risk groups. However, the value of the con­ reasons for poor implementation. clusions is substantially reduced owing to lack of information on (a) the adaptivity or the Some additional symptoms and manifes­ individual capacity of risk-free persons to tations which are not usual features of adapt, and (b) the degree of actual compen­ endemic fluorosis were also evident in the sation made by persons at risk. The evaluation Guizhou population, suggesting that factors of health has to be based on adaptivity studies other than fluoride may be influencing the in order to recognize a person's resistance to occurrence and development of endemic fluo­ pathogenic factors and the degree of compen­ rosis. From epidemiological and experimental sation through processes of adaptation. Since studies on the potential influences of other a person's adaptivity and physical working substances emitted by the burning coal, such capacity correlate well in the majority of as aluminium and arsenic, it appears that fluo­ cases, the use of exercise tests in health eva­ ride and arsenic in combination may have a luation is justified in the following situations. synergistic role in producing ill-effects. • Decreased mobility or reduced motor Li Oasheng function (hypokinesia) can lead to degener­ Institute of Endemic Diseases Control, ative changes in the organs concerned, Guizhou Provincial Health and Anti-Epidemic Station, decreased function, loss of fitness, and the Guiyand 55001, People's Republic of China development of risk factors and subclinical conditions. A test for evaluation of func­ T. W. CutTess HRC Dental Research Unit, PO. Box 27007, tional capacities as well as a diagnostic Wellington, New Zealand method for establishing subclinical symp­ (Please address correspondence to Dr Cutress.) toms are necessary. Exercise tests provoke the appearance of subclinical symptoms. • Increased fitness and a higher resistance to pathogenic conditions can result from "Health" evaluation: use of physical health promotion through physical train­ exercise tests ing, which improves the general adaptation The frequent use of the term "health" in a mechanism (2). Exercise tests can be useful negative sense was deplored by Copplestone for health promotion by physical training. in World health forum a few years ago (1). • Exercise tests can provide information for The problem is not only a semantic one the assessment of individual (ontogenetic)

114 World Health Forum. Volume 11 • 1996