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Biomedical subjects

A A Wibowo

Publications and source records attributed to A A Wibowo.

At least 19 recordsLinked to original sources
PubMed1989

Standard setting in occupational health: "philosophical" issues.

This paper discusses various "philosophical" issues in standard setting in occupational and environmental health, i.e., general principles, actual procedures for standard setting, inter- and intra-agency discrepancies in procedures and criteria, and choices and decisions in the preparation of criteria documents and in the evaluation of the toxicology databases. Unpublished, possibly confidential information should be made available to expert committees, workers, and the general public. There is an urgent need to improve the validity of the toxicology databases that have to underpin occupational and environmental exposure limits. Standard setting requires various ethically loaded choices and decisions by experts, employees, managers, government officials, and politicians.

Animals↗
PubMed1988

Short-term occupational exposure limits: a simplified approach.

This paper presents a simplified proposal for setting health standards based on short-term exposure limits (STEL). It presents an alternative to the approach by the German MAC Commission: with only three instead of five categories, no fixed excursion factors, but ranges; more restrictive duration of sampling; no fixed frequencies of the number of accepted excursions per workshift.

Air Pollutants, Occupational↗
PubMed1988

Exposure of dentists and assistants to mercury: mercury levels in urine and hair related to conditions of practice.

A study of 162 dentists' and their assistants' mercury levels in hair and urine, and of questionnaire items regarding mercury consumption, revealed some striking relations. The mercury concentrations in both hair (Hg-H) and urine (Hg-U) were somewhat higher in the dentists than the assistants. There was no relation between concentrations in hair and urine. The method of condensation of amalgam was positively related to Hg-U; the vibration method was negatively related. Hg-U was also positively related to number of fillings and hours in own practice. The relation of Hg-U to ventilation in the surgery applied only to the dentists.

Dental Amalgam↗
PubMed1987

Occupational exposure to lead and blood pressure: a study in 105 workers.

A group of workers, occupationally exposed to lead and cadmium compounds (n = 53), was compared to a group of workers not exposed to these metals (n = 52). The average values of systolic, diastolic, and mean blood pressure were found to be higher in the exposed group (p less than 0.05). In contrast with the correlation between CdU and blood pressure, the correlation between PbB and systolic and mean blood pressure remained statistically significant after controlling for age and pulse rate (r = 0.22, p less than 0.05). The prevalence of potential hypertension (defined as systolic blood pressure greater than or equal to 160 mm Hg and/or diastolic blood pressure greater than or equal to 95 mm Hg and/or under treatment for hypertension) was higher in the exposed group, but the observed relative risk was not statistically significant: relative risk = 1.91 (95% confidence limits, 0.90-4.05). Furthermore, a significant correlation between PbB and Hgb (r = -0.28, p = 0.004) was observed. Differences in kidney function, as assessed in this study, were not detected.

Adult↗
PubMed1986

Levels of metals in hair of young children as an indicator of environmental pollution.

In 1982 the levels of lead (Pb), cadmium (Cd), vanadium (V), copper (Cu), and selenium (Se) were determined in hair of 231 four- to five-year-old children. The objective was to explore the feasibility of using metal-in-hair levels in groups of children as an indicator of environmental pollution. The study was carried out in four areas, which were assumed to differ in ambient pollution by metals. A questionnaire on personal data, socioeconomic status, intake of beverages, and life-style was completed by the parents. The metal-in-hair levels covered a large range. The variables pertaining to location together with sex, presence of a garden, and drinking of coffee and/or tea explained 32% of the variance of Pb, 24% of the variance of Cd, and 21% of the variance of V. The total variance explained by all measured questionnaire items was at best 38%. The location was the most important factor. Cu and Se levels did not differ between the locations.

Child, Preschool↗
PubMed1985

Trace metals and coronary heart disease risk indicators in 152 elderly men (the Zutphen Study).

Information about trace metals and coronary heart disease risk indicators was collected in 1977 among 152 men aged 57-76 years in the town of Zutphen, the Netherlands. Serum zinc, serum copper, blood cadmium, and blood lead were determined by atomic absorption spectrometry and serum lithium by flame emission spectrometry. After uni- and multivariate regression analysis, the following statistically significant relations were found: serum zinc was inversely related to resting heart rate; serum copper was positively related to cigarette smoking and inversely to high density lipoprotein cholesterol; blood cadmium was strongly positively related to cigarette smoking and inversely to Quetelet index; the positive relation between blood lead and cigarette smoking was of borderline significance; and blood lead was related to blood pressure, with the relation being stronger for systolic than for diastolic blood pressure.

Aged↗
PubMed1983

Trace element levels in hair of eight-year-old children.

A study of trace element levels in hair was performed on 183 eight-year-old schoolchildren living in Bijlmermeer, a suburb of Amsterdam, the Netherlands. Microlevel-elements, such as Au, Co, Ag, Se and Cd, and macrolevel-elements, such as Pb, Cu, Fe and Zn, were analyzed using the NAA and AAS methods. The total group of children was divided into subgroups, according to ethnic origins: Caucasian boys and girls, Hindustani children and a Surinamese rest group. The relation between element levels in hair and nutritional status, anthropometric and haematological variables were studied. Most levels corresponded reasonably with literature data. The iron in hair may be positively related to daily dietary intake of iron.

Child↗
PubMed1982

Absence of an effect of lead acetate on sperm morphology, sister chromatid exchanges or on micronuclei formation in rabbits.

The influence of lead on sperm morphology, sister chromatid exchanges or on micronuclei formation was studied on male rabbits after exposure to doses of 0, 0.25, and 0.50 mg lead acetate/kg body weight subcutaneously injected three times a week during 14 weeks, each on a group of five rabbits. At the end of exposure phase the lead in blood concentrations of the three groups of rabbits were 0.32, 2.57, and 2.97 mumol/l respectively. The results did not show any evidence of treatment related effects on sperm count or on morphologic abnormalities of the sperms, neither on the histopathology of the testis. Statistical analysis of the number of sister chromatid exchanges per metaphase in lymphocytes indicated no differences between the groups. Also no dose dependent effect was observed on the relative number of micronuclei in bone marrow erythrocytes. The different susceptibility to lead in different organ systems of the rabbits was discussed.

Animals↗
PubMed1982

Biological assessment of exposure in factories with second degree usage of cadmium compounds.

Biological assessment of occupational exposure to cadmium in five different factories with low-level second degree usage of Cd-compounds has been carried out. In 124 exposed and control male workers the following measurements, were performed: cadmium in blood (CdB) and urine (CdU), B2-microglobulin (B2M), creatinin in urine (Creat), hemoglobin (Hb) and hematocrit (Ht). Analysis of 34 pairs of workers matched according to age, smoking habits, ethnic origin and factory, established a significant difference only in CdU, the geometric means being 0.67 microgram/g Creat in the exposed group and 0.48 microgram/g Creat in the control group. Significant correlation was found between CdU x age and CdB x smoking habits. Multiple regression analysis showed that for each year increase in age CdU increased 3%, for each percent increase of CdB CdU increased 0.28%; for each cigarette smoked per day CdB increased 1.6%. It is concluded that in this type of work the low external cadmium exposure does not express itself in different CdB-levels, but only in different CdU-levels, indicating an increased body burden due to long term low levels occupational cadmium exposure. In biological assessment of exposure to Cd, it is essential to take age and smoking habits fully into account.

Adult↗
PubMed1981

The effect of testosterone administration on lead induced zincprotoporphyrin in blood concentration in castrated male rabbits.

The influence of testosterone propionate on the concentration of zincprotoporphyrin in blood (ZPP) of castrated lead treated rabbits was investigated. The experimental design allowed comparison of the relative ZPP increase (RZI) in testosterone treated and non testosterone treated rabbits. Testosterone was administered by subcutaneous injection of 3 mg/kg body weight/day for 7 consecutive days directly prior to the lead exposure, which was performed by subcutaneous injection of 0.50 mg lead acetate/kg body weight, three times a week for 7 weeks. No effect was found on the hemoglobin concentration (Hb) and hematocrit (Ht) and on the increase of body weight during the experiment. But the increase of RZI in the non testosterone treated rabbits was significantly steeper and earlier than in the testosterone treated group. The possible consequences of the findings had been further commented on.

Animals↗
PubMed1981

Ultrastructural changes in the kidneys of rabbits treated with lead acetate.

Electron microscopical studies were carried out on the kidneys of rabbits given s.c. injections of 0 (control), 0.25 or 0.50 mg lead acetate/kg b.w. 3 times a week during 14 weeks. At the end of the experimental period the animals had lead blood levels of 60, 500 and 600 micrograms/l whole blood respectively. Treatment-related renal changes were found in the proximal tubules; they consisted of a dose-related increase in the amount of lysosomes in epithelial cells of the convoluted part, and of severely damaged cells and loss of brush border in the straight part. There was also an increase in lysosomal tubular inclusions, which are considered characteristic of lysosomes of the proximal tubular cells of the rabbit kidney. The significance of these findings for assessing the risk of occupational exposure to lead is briefly discussed.

Animals↗
PubMed1980

Different effects on hemesynthesis in male and female rabbits treated with lead acetate.

The feasibility of an animal model was investigated to study the mechanisms underlying the difference in response to inorganic lead exposure between males and females, as shown in the different increase of zincprotoporphyrin (ZPP) in blood concentrations. Groups of rabbits of both sexes received s.c. injections of 0.25 (L) or 0.50 (H) mg lead acetate/kb b.w. or a control solution three times a week during 14 weeks. A steep increase of blood lead (PbB) was found in the first 4 weeks of exposure; in subsequent weeks PbB leveled off. In the L-group PbB increased to 775--1387 microgram/l rbc and in the H-group to 892--1522 microgram/l rbc. In female rabbits ZPP increased earlier than in males; the relative increase of ZPP was stronger in female rabbits, particularly in the H-group. No effect on Hb, Ht and body weight was observed. The response to lead in female and male rabbits is very similar to that observed in humans.

Animals↗
PubMed1980

The feasibility of using lead in hair concentration in monitoring environmental exposure in children.

The feasibility of lead in hair as an indicator of lead exposure has been compared to that of lead in blood and zinc protoporphyrin in blood levels in 1--3-year-old children living within 1 km of a lead smelter. Lead exposure was measured as lead in house dust, outdoor and indoor lead in air concentrations, outdoor and indoor lead depositions, and subjective assessment of indoor dustiness. Lead in blood ranged from 51-353 microgram/l and lead in hair from 0.8-114 microgram/g. It can be concluded that within the range of environmental exposure studied, and for the age group concerned, measurement of lead in blood and of the zinc protoporphyrin in blood levels appear to be better biological parameters to assess both total environmental exposure and health risk than measurement of lead in hair level alone.

Child, Preschool↗