Geographic variations in the composition of ivory of the African elephant (Loxodonta africana).

Tracing the source of origin of illegal ivory will contribute to the identification of poorly managed game parks and facilitate steps taken to prevent the African elephant from becoming extinct. This study was aimed at establishing a database on the composition of ivory obtained from elephant sanctuary areas in Southern Africa. Fragments of elephant ivory from seven geographically distinct areas in South Africa, Namibia and Botswana were analysed for inorganic and organic content. A total of 20 elements was detected in the inorganic fraction of ivory, some in concentrations as low as 0.25 microg/g. The concentrations of calcium, phosphate, magnesium, fluoride, cobalt and zinc showed statistically significant differences (p < 0.007) between ivory obtained from different regions. Analyses of the organic fraction identified 17 amino acids. Ivory from arid regions showed significantly lower proline plus hydroxyproline content and under-hydroxylation of lysine residues. This study indicates that chemical analyses of ivory could be beneficial in tracing the source of illegal ivory.

Preliminary screening of plants used in South Africa as traditional herbal remedies during pregnancy and labour.

Agapanthus africanus, Pentanisia prunelloides and Gunnera perpensa are indigenous plants which are used in traditional herbal remedies during pregnancy and childbirth. A crude decoction of each plant was tested on isolated rat uterus and ileum for pharmacological activity. Agapanthus africanus and Pentanisia prunelloides exhibited direct smooth muscle activity on the uterus and ileum preparations, while Gunnera perpensa showed direct smooth muscle activity on the uterus only. All the plant extracts potentiated the initial response of the uterus to oxytocin but Pentanisia prunelloides reduced the maximum response of the uterus to oxytocin. The Agapanthus africanus and Pentanisia prunelloides extracts potentiated the initial response of the ileum to acetylcholine but all the plant extracts inhibited the maximum response of the ileum to acetycholine.

Evaluation of a new chelating agent for cadmium: a preliminary report.

The Plasma Mobilizing Index parameters of the newly synthesized chelating agent THP-12-ane N4, determined by computer simulation studies, have indicated that this chelating agent might be a good antagonist for cadmium intoxication. Experiments conducted on rats confirmed this observation and showed that THP-12-ane N4 might have the ability to chelate and mobilize cadmium in vivo.

Pesticide exposure and cholinesterase levels among farm workers in the Republic of South Africa.

A preliminary survey was undertaken to establish the extent of pesticide exposure in a farming community. The area under investigation included a coffee plantation in the northern region of South Africa. Cholinesterase levels in red blood cells and plasma were used as markers to monitor the extent of organophosphate and carbamate exposure. Sixty-nine farm workers with specific pesticide exposure were selected for the study, and the frequency of the different symptoms which may be related to pesticide exposure was determined by interview and questionnaire. Of the workers, 77% had their red blood cell cholinesterase levels below the normal reference range, while 27% of the workers had depressed plasma cholinesterase levels.

Monitoring of air for microbial and metal contamination at selected sites in the vicinity of Johannesburg, South Africa.

A preliminary survey was undertaken to identify air contamination in the vicinity of industrial, residential and hospital sites. In many developing countries, poor town planning has resulted in growth of residential and commercial sites in close proximity to the industrial works, without the provision of a buffer zone. As prevailing winds blow across the industrial works to the other areas, undesirable pollution may be experienced. Before steps are taken to reduce factory emissions, the impact of the industry on the surrounding area needs to be clearly defined. In this study, the total particulate matter and the level of microbial contamination at the selected sites is reported. The elemental composition of the particulate matter is described.

Fluoride in workplace air and in urine of workers concentrating fluorspar.

The urinary fluoride concentrations of workers exposed to calcium fluoride (CaF2) during fluorspar processing were measured. Personal dust measurement showed that the mean occupational exposure to fluoride for 12 workers in the most dusty environment was 24.3 mg/m3, which is 9.7 times the threshold limit value (TLV) of 2.5 mg/m3. Exposure was below the TLV for the remaining 23 workers. Urinary fluoride concentrations were measured pre- and postshift. The heavily exposed workers had a mean preshift concentration of 3.3 mg/liter (range 1.4-8.5 mg/liter), only slightly higher than the mean of 2.8 mg/liter (range 1.3-4.2 mg/liter) in the workers with fluoride exposure below the TLV. Four of the preshift concentrations exceeded the recommended upper limit of 4 mg/liter. The mean postshift concentration for workers exposed above the TLV was 4.4 mg/liter (range 2.4-7.1 mg/liter) and the difference between pre- and postshift concentrations was significant (p less than 0.05). Only one urinary concentration exceeded the recommended upper limit of 7 mg/liter. There was poor correlation between intensity of environmental exposure to fluorspar and postshift fluoride concentration in the urine. Eighteen workers provided a urine sample 7-14 hr after the end of a shift. The mean fluoride concentration was 4.7 mg/liter (range 2.4-11.7 mg/liter), which exceeded their postshift concentration by 0.2 mg/liter. These results indicate that the low aqueous solubility of fluorspar reduced the biologic availability of the fluoride ion but that this did not prevent excessive fluoride absorption in some workers.