Evidence of undue lead exposure in Cape Town before the advent of leaded petrol.

Lead concentrations were determined in the exhumed teeth of 28 people who lived in the Cape Town area before the combustion of leaded petrol (i.e. before 1922). The lead content of circumpulpal dentine was analysed by graphite-furnace atomic absorption spectrometry. The mean lead level in the dentine of primary teeth (N = 6) was 109 micrograms/g, while that in secondary teeth (N = 22) was 315 micrograms/g. The current lead levels in circumpulpal dentine of Cape Town residents are reported to be 74 micrograms/g and 16 micrograms/g for primary and secondary teeth respectively. It was found that lead pollution of the human body during the period 1812-1922 in the Cape Town area was substantially higher than at present. We conclude that the main reasons for this were the widespread use of lead piping and soldering of water tanks, which resulted in a higher incidence of lead poisoning than that attributable to leaded petrol.

Effect of the reduction of petrol lead on the blood lead levels of South Africans.

Lead has no metabolic role in the human body and its presence is associated with various toxic effects. Several countries have responded to this health hazard reducing petrol lead additives or entirely eliminating them. Studies have shown that there has been a resultant fall in blood lead levels of the particular populations. This study reports on the progressive decline in blood lead levels of South Africans during the period 1984-1990 which coincided with a stepwise reduction in petrol lead additives from 0.8 g/l to 0.4 g/l. During this period the blood lead levels of Cape Town city dwellers decreased significantly (P < 0.01) from 9.7 micrograms/dl to 7.2 micrograms/dl. This blood lead level compares favourably with that of other more industrialized countries with less lead in their petrol. Therefore, the authors question the need for further reduction of petrol lead content bearing in mind the considerable financial burden that such a step will entail and the dubious health advantage that may be gained.

Burning mouth syndrome. Evaluation of multiple variables among 85 patients.

The relationship between burning mouth syndrome and 48 variables was investigated in 241 patients, 45 years old and older, who had attended the Oral Medicine Clinic of the Faculty of Dentistry, University of Stellenbosch during a period of 4 years. A total of 85 cases of burning mouth syndrome were diagnosed in 65 women and 20 men. Statistically significant relationships (p < 0.05) were found with self-medication, xerostomia, and other salivary disturbances in both men and women with burning mouth syndrome when compared with their respective controls. Among the women with BMS, significant relationships were also found with anemia, inadequate diet, chronic infection, hormone therapy, ulcerative/erosive lesions, and atrophy. In contrast men with BMS showed statistically significant relationships between taking prescribed medication, central nervous system disturbances, gingivitis, and denture-related problems. In addition, significant associations were related to variables such as psychogenic factors, regurgitation, flatulence, and periodontitis.

Burning mouth syndrome: a selective review.

Burning mouth syndrome (BMS) has been associated with a wide variety of etiological factors. A selective review of these factors as well as an approach to the management of this condition are presented.

Lead reduction of petrol and blood lead concentrations of athletes.

In 1984, it was determined that the blood of long-distance runners in South Africa contained unacceptably high concentrations of lead. Subsequently, the petrol lead level in South Africa was reduced from 0.8 g/l to 0.4 g/l. In view of this reduction, a followup investigation of its effect on the blood lead concentration of South African runners was undertaken. Blood lead samples were analyzed by graphite furnace atomic absorption spectrophotometry. The mean values of blood lead concentrations dropped from 52 to 13 micrograms/dl and from 20 to 8.5 micrograms/dl for the urban and rural trainers, respectively. A highly significant decrease in blood lead levels was found and was mainly attributable to the reduction in the petrol lead levels. The blood lead results for rural trainers indicated that there still exists a certain degree of lead pollution in athletes from nonremote areas.

Failures of endocarditis prophylaxis: selective review of the literature and a case report.

Patients at risk for developing infective endocarditis require antibiotic prophylaxis before bloody dental procedures. However, despite prophylactic measures, some patients still develop the infection. A selective review of the literature is given and a case report of prophylactic failure in a high risk patient is presented.

Epidemiology of oral precancer and cancer.

Although a large number of lesions and conditions have been designated as premalignant, most of these diseases have a very low incidence. Furthermore, only a small percentage undergo malignant transformation. In this article, premalignant changes of the oral mucosa are described and contributory factors that enhance their malignant transformation are identified. The largest single risk factor is atrophy of the oral mucosa. Oral submucous fibrosis, tobacco use and iron deficiency anaemias enhance the risk of malignant transformation. The location of lesions is also considered, since certain sites display a greater predilection to malignant transformation. The epidemiology of oral squamous cell carcinoma among the South African populations is considered and compared with figures from other countries. The impact of urbanisation and changing habits have led to a gradual move towards equalization of the incidences for males and females. The tongue is the most commonly involved site in all South African racial groups. However, there are differences in site distribution. For instance, among whites there is a greater predilection for carcinoma of the floor of the mouth, while among blacks the palate is more frequently involved. The incidence is highest during the 7th decade.

Unusually high circumpulpal lead concentrations as valid evidence of lead intoxication.

A case is reported of a 59-year-old male who had been employed continuously as a motor technician for 32 years. During the latter period of his employment he gradually developed a number of the signs and symptoms typically manifested by persons suffering from lead intoxication. Five years after the termination of his employment, the lead content in the circumpulpal dentine of 2 of his teeth was determined and found to be more than 7 times higher than that of the controls. Thus, the probability of lead intoxication is supported very strongly.

Blood lead levels of South African long-distance road-runners.

Road runners are exposed to vehicular exhaust aerosols which are a major source of atmospheric lead pollution in those countries where lead additives are incorporated in petrol. The purpose of this study was twofold: the authors wished to determine the blood lead levels of South African road runners, and they wished to investigate the influence of various environments on such levels. Blood samples were obtained by the finger-prick technique and analyzed for lead by graphite furnace atomic absorption spectrophotometry. The results were analyzed statistically and compared with control samples from a selected urban nonrunning population and a remote rural population, respectively. The mean blood lead levels obtained were 20.1 micrograms/dl, 51.9 micrograms/dl, 45.8 micrograms/dl, and 53.00 micrograms/dl for the rural trainers, urban trainers, Two Oceans pre-race, and Two Oceans post-race samples, respectively. The mean level for the selected urban control was 9.7 micrograms/dl. The results suggest that road runners are exposed to increased lead inhalation and that atmospheric lead levels differ in urban and rural areas of South Africa.

Blood lead levels in motor mechanics.

The whole-blood lead levels of a group of motor mechanics in the Cape Peninsula were determined. Blood was analysed using a graphite furnace atomic absorption spectrometer. The mean whole-blood lead levels of the motor mechanics and of urban controls were 28,4 micrograms/dl and 9,7 micrograms/dl respectively, and comparison of these with that of a group from an unpolluted rural area (3,4 micrograms/dl) revealed highly significant differences.

Blood lead levels in a remote, unpolluted rural area in South Africa.

The whole-blood lead levels of 14-16-year-olds in a remote, unpolluted rural area (Wupperthal, north-western Cape Province) were determined. Graphite-furnace atomic absorption spectrometry was used to analyse lead levels. The mean whole-blood lead level was found to be 3,4 micrograms/dl. This value should also be considered to be representative of the natural 'background' whole-blood lead level of South Africans.