Low frequency of infertility among workers in a borate processing facility

In order to rule out the possibility of omitting some individuals in the study at field visits described in previous articles, either because of the reluctance of the subject or because of his appointment elsewhere, fertility and infertility states of borate workers of the Borax and Acid Plants in Bandirma, Balikesir are given. Balikesir is one of the four provinces with large borate deposits of Turkey, and Bandirma is 1 of its 19 districts. This county is relatively far away from borate deposits, and drinking water piped out through the springs has a boron amount between 0.10 and 0.82 ppm B. That the participants are occupationally exposed to the mineral in essence is therefore conceivable. At the first phase of the investigation, 191 workers were interviewed, as detailed previously. Among these, there were six infertiles of the primary type with a rate 3.1%. Boron-unrelated infertile couples among sibs were found to be 2.6–3.6%, and 3.2% for three-generation marriages—none being higher than those revealed in different sets of controls. In the second stage of work, computerized files of all workers of the facility and all employees of the general management sharing the same location were checked without an interview. Twenty-four subjects (3.4%) out of 712 workers were childless versus 2.7% among 108 employees, and 2.2% among 91 workers of a distantly located sulfuric acid plant of the same complex. The differences were not significant, and these recent findings support the conclusion already reached almost unambiguously that boron exposure at the present levels does not interfere with human reproduction.     

Trace element determination in scalp hair of people working at a copper smelter

Instrumental neutron activation analysis was performed to assess the exposure degree of a worker group from a copper smelter. The results were compared with data of inhabitants of Kinshasa and Bandaka in Zaire. Excessive concentrations of Mg, Ca, V, Co, Cu, As, and Cd were observed in the investigated group. The distribution patterns of trace elements are shown. The plots of Cu concentration relations to selected elements, i. e., As, Co, and Zn, showed a plateau at about 300 ppm of Cu.     

Influence of 50 Hz electric and magnetic fields on the pulse rate of human heart

This investigation studied the effects of 50 Hz electric and magnetic fields on the pulse rate of the human heart. The ECG (electrocardiograms) of 41 male volunteers were recorded with a Holter recorder. Twenty-six subjects were measured in and outside real fields, and 15 subjects were measured in and outside “sham” fields. The blood pressure and EEG (electroencephalogram) were also measured, but this article presents only the results of ECG recordings. The measurements took 3 h. The subjects were first sitting for 1 h outside the fields, then 1 h in the real or “sham” fields, and then, again, 1 h outside the fields. The electric field strength varied from 3.5 to 4.3 kV/m and the magnetic flux density from 1.4 to 6.6 μT. An analysis of the ECG recordings showed that the subjects' pulse rates were the same in and outside the fields. No response occurred when the subjects were exposed to real or “sham” fields. © 1994 Wiley-Liss, Inc.     

Renal dysfunction of cadmium-exposed workers residing in a cadmium-polluted environment

Human exposure to cadmium may occur in both occupational and general environments. We were interested in determining whether a combination of occupational and environmental exposure to cadmium results in different levels of severity of renal dysfunction relative to that arising from environmental or occupational exposure alone. We selected 44 residents, who once were employed in a smelter and lived in a cadmium-polluted area, as group A. Another 88 subjects, who never worked in the plant, but lived in the same area, were selected as group B. Group C consisted of 88 subjects who had no history of occupational exposure to cadmium and lived in a non-cadmium-polluted area. Statistical analysis demonstrated that there was no significant difference in age or gender among the three groups, nor were there significant differences in smoking habits. The prevalence of renal dysfunction as indicated by increased excretion of beta2-microglobulin (B2M), N-acetyl-beta-D-glucosaminidase (NAG) and albumin (ALB), was higher in group A than in group B. This finding suggests that exposure to cadmium both occupationally and environmentally results in a higher prevalence of renal dysfunction, relative to those who are exposed to cadmium only in the general environment. Therefore, this specific population, who once were occupationally exposed to cadmium and lived in polluted areas, should be identified. Furthermore, health examinations of this population should be conducted in time to prevent further health damage induced by cadmium exposure.     

Mercury in human hair and blood samples from people living in Wanshan mercury mine area, Guizhou, China: an XAS study

Human hair and blood samples from persons living in the town of Wanshan, a mercury mine area in Guizhou Province of China, were collected and the quantitative speciation and structural information of Hg and S in hair samples and of Hg in erythrocyte and serum samples were studied using X-ray absorption spectroscopy. Least-squares fitting of the X-ray absorption near-edge spectra found that inorganic mercury is the major mercury species in hair samples (91.74%), while inorganic and methyl mercury are both about 50% of total mercury in RBC and serum samples, which is in agreement with the data obtained by acidic extraction, fractionation of Hg(2+) and CH(3)Hg(+) and quantification by ICP-MS. Curve-fitting analysis revealed that the Hg-S bond length and coordination number in hair were 0.248+/-0.002 nm and 3.10, respectively, while the S-Hg bond length and coordination number in hair were 0.236+/-0.002 nm and 4.05. The Hg-S bond length and coordination number in RBC were 0.251+/-0.003 nm and 4.09, respectively, while they were 0.228+/-0.002 nm and 4.08 in serum, respectively. The techniques for speciation, structural and binding information described in this study will find the potential application in similar studies of other elements.     

Lead levels in bone and hair of rats treated with lead acetate

The use of hair and bone as media in evaluation of lead exposure was investigated in this study. For 12–16 wk rats were given tap water containing lead acetate in the following concentrations: 41.7 mg Pb/L, 83.3 mg Pb/L, and 166.6 mg Pb/L. The animals were sacrificed every 4 wk and their tibia bones and hair were collected for determination of lead content. In control animals, the lead level amounted to 1.2 μg/g (range 0.8–1.3 μg/g) and 0.7 μg/g (range 0.4–2.0 μg/g) in bone and hair, respectively. In the treated rats the accumulation of lead in bone and hair occurred in a dose-dependent manner. A positive corelation (r=0.876) was established between the lead levels in bone and hair of the rats. The regression equation was as follows: μg Pb/g bone=0.842×μg Pb/g hair+1.868. After discontinuation of exposure, a significant decrease in the lead content in bone and hair was noticed. About 9 wk after cessation of treatment, the lead content in hair declined to the pre-exposure level, but 64% of the maximal lead concentration did remain in bone. The results of this study indicate that during a continuous exposure the lead level in hair reflects its content in bone. Such phenomena did not occur during the postexposure period.     

Health outcomes of road-traffic pollution among exposed roadside workers in Rawalpindi City,Pakistan

To document ill-health effects of air pollution on the local inhabitants, we analyzed the self-reported health issues associated with the inhalation of road traffic on daily basis. For this purpose, a revised version of ALS-DLD-78S questionnaire was administered, comprising the personal information and details related to the clinical history of the surveyed population (i.e. n = 580). Five dependent (outcome) variables, including chest pain, redness of eyes, shortness of breath, eye-tearing, and skin-itching were taken into account. The results revealed that ～80% of the surveyed population were directly or indirectly exposed to road traffic, and the incidence of chest pain among exposed individuals was estimated to increase with age (odds ratio (OR) = 6.49; 95% confidence interval (CI) = 1.46–28.81), especially among cardiac patients (OR = 13.87; 95%-CI = 3.28–58.61). However, the shortness of breath was predominantly observed among those who reported to have asthmatic symptoms (OR = 32.84; 95%-CI = 15.59–69.15) and cardiovascular symptoms (OR = 13.8: 95%-CI = 3.63–52.41). In case of itching, the population along the roadside were more vulnerable to exposure (OR = 5.79; 95%-CI = 2.81–11.93). While, exposure to traffic exhaust could be attributed to ～3.13% rise in the incidences of redness of eyes among general population, the outcomes of this survey show that daily exposure to traffic pollution is an important health concern for the urban population in general, as well as for various occupational groups in particular, working in outdoor environment.     

Lead concentrations in cortical and trabecular bones in deceased smelter workers

The aim of the study was to compare bone lead concentrations in cortical and trabecular bones in long-term exposed primary copper and lead smelter workers, and to relate the measured concentrations to the previous lead exposure of the workers. Lead concentrations in seven bones (trabecular: sternum, vertebrae, iliac crest, rib; cortical: femur, left forefinger, and temporal bone) were determined by electrothermal atomic absorption spectrometry in 32 male, long-term exposed copper and lead smelter workers, and compared with levels in 10 male occupationally unexposed reference persons. A time-integrated blood lead index (cumulative blood lead index, CBLI) was calculated for each worker. The lead levels in the seven studied bones were all significantly higher in active and retired lead workers as compared with the reference group (p相似文献   

Arsenic exposure levels of petrochemical workers in three workplace settings in Rayong Province,Thailand

Background: Crude oil and natural gas are often contaminated with arsenic. As a carcinogen, arsenic contamination in the workplace is of concern, particularly when urinary arsenic levels are higher than the standard. The aim of this study was to identify exposure sources of arsenic among petrochemical workers. Methods: A total of 188 operators and 30 office workers participated in the study. Ninety-three workplace air samples, three main meals in five consecutive days, and drinking water were collected from each participant. Urine was collected at the end of the day after the last food sample was collected from each subject. Urine samples where arsenic concentration exceeded 100 mg/L were further analyzed to identify species. Results: The average arsenic concentrations in operators' and office workers' food and urine were 0.55 ± 1.00 and 0.49 ± 0.67 mg/kg; and 76.43 ± 107.36 and 149.92 ± 200.28 mg/L, respectively. The arsenic concentrations in air and water were well below their standards. The urinary arsenic correlated well with arsenic in the food but not in the air and water. Conclusion: Occupational exposure to arsenic among operators and office workers was lower than 1% TLV (Threshold limit value) and did not differ significantly. The major source of arsenic exposure Q2 was food.     

Lack of correlation between blood lead and serum prolactin levels among lead exposed workers

A cross sectional case (241 males occupationally exposed to lead)–control (102 males unexposed to lead) study was performed with the aim of evaluating the relationship between serum prolactin (S-PRL) and lead blood (PbB) levels. A meta-analysis of S-PRL levels in similar studies was also carried out. No difference of S-PRL between groups or any relationship between PbB and S-PRL levels was found. The meta-analysis showed a slight increase of S-PRL levels among exposed people, the weighted means falling within the reference values of the biomarker. The results do not support a routine use of S-PRL as a biomarker of effect in lead exposed workers.     

Influence of 50 Hz electric and magnetic fields on the human heart

This investigation studied the effect of 50 Hz electric and magnetic fields on the human heart. The electrocardiograms of 27 transmission-line workers and 26 male volunteers were recorded with a Holter recorder both in and outside the fields. The measurements took from half an hour to a few hours. The electric field strength varied from 0.14 to 10.21 kV/m and the magnetic flux density from 1.02 to 15.43 μT. Analysis of the ECG recordings showed that extrasystoles or arrhythmias were as frequent outside the field as in the field. In some cases a small decrease in heart rate was observed after field exposure. © 1993 Wiley-Liss, Inc.     

Melanocyte stem cells: a melanocyte reservoir in hair follicles for hair and skin pigmentation

Most mammals are coated with pigmented hair. Melanocytes in each hair follicle produce melanin pigments for the hair during each hair cycle. The key to understanding the mechanism of cyclic melanin production is the melanocyte stem cell (MelSC) population, previously known as 'amelanotic melanocytes'. The MelSCs directly adhere to hair follicle stem cells, the niche cells for MelSCs and reside in the hair follicle bulge-subbulge area, the lower permanent portion of the hair follicle, to serve as a melanocyte reservoir for skin and hair pigmentation. MelSCs form a stem cell system within individual hair follicles and provide a 'hair pigmentary unit' for each cycle of hair pigmentation. This review focuses on the identification of MelSCs and their characteristics and explains the importance of the MelSC population in the mechanisms of hair pigmentation, hair greying, and skin repigmentation.     

Correlation of mercury with selenium in human hair at a typical mercury-polluted area in China

The levels of mercury (Hg) and selenium (Se) and their correlation in human scalp hair of 29 pairs of pregnant women and their newborns living at a high-Hg and low-Se area, the Second Song-Hua-Jiang River System, have been studied by instrumental neutron activation analysis. Our results indicate that the Hg level in infant hair samples are roughly close to that in their mothers, whereas the Se level in infants is much higher. Furthermore, the molar ratios of Se/Hg in newborns are also 40% higher than those in mothers. It demonstrates that infants are able to absorb more selenium from their mothers’ bodies to protect against or alleviate the intoxication of Hg. This “autoprotective mechanism” likely plays a critical role during fetal development. The possible chemical species of Hg and Se in hair is also discussed.     

Chromium content in the hair of children and students in Southern Poland

Chromium concentrations in hair were compared in groups of children and students from Southern Poland. There were no statistically significant differences (atp>0.05) between girls and boys. The results are similar to those found by other authors in different countries.     

Assessment of genotoxicity in female agricultural workers exposed to pesticides

Objective: This study was designed to determine the genotoxic effect of exposure to a mixture of pesticides in 106 female agricultural workers employed in cotton fields from India.

Methods: Comet, micronucleus and chromosomal aberrations tests were carried out in peripheral blood lymphocytes. Micronucleus test was also performed in buccal epithelial cells. Levels of antioxidant enzymes, RBC acetylcholinesterase and hematological parameters were analyzed in the blood samples of the study subjects.

Results: The results indicated significant DNA damage, increased frequency of micronuclei and chromosomal aberrations in the exposed subjects (p?<?0.05). The levels of antioxidant enzymes were significantly lowered and the rate of lipid peroxidation was elevated in the exposed subjects.

Conclusion: The outcome of the study revealed an increased risk of genotoxicity and health implications in female agricultural workers.     

Root hair formation at the root-hypocotyl junction in CPC-LIKE MYB double and triple mutants of Arabidopsis

In Arabidopsis thaliana, R3-type MYB genes, CAPRICE (CPC) and its family of genes including TRIPTYCHON (TRY), ENHANCER OF TRY AND CPC1 (ETC1), ETC2 and CPC-LIKE MYB3 cooperatively regulate epidermal cell differentiation. Root hair formation is greatly reduced by a mutation in CPC, and try and etc1 enhance this phenotype. In this study, we demonstrate that CPC, TRY and ETC1 are also involved in root hair formation at the root-hypocotyl junction. The cpc try and cpc etc1 double mutants showed a reduced number of root hairs in that area. Additionally, the expression of ETC1::GUS was higher near this area. These results suggest that CPC family of genes also cooperatively regulates root hair formation at the root-hypocotyl junction in unique ways.     

Determination of copper and zinc levels in human hair

The Cu and Zn levels of both 607 men (1–85 y old) and 649 women (1–92 y old) were determined by atomic absorption spectrometry. Sex does not influence Cu (14.89±0.89 μg/g and 15.26±0.79 μg/g hair for males and females, respectively) and Zn contents (200.97±9.68 μg/g for men and 209.81±9.49 μg/g hair for women). Age influences Cu and Zn concentrations, but only significantly in females: Cu levels decrease over 60 y of age; whereas Zn levels increase significantly from age groups 2–5 to 20–40 years. Hair color influences Cu concentrations in both males and females. In males, white hair containes less Cu than black hair; in females, white hair's Cu levels are significantly lower than those of dark blond, red, light brown, and brown hair. There are no significant differences in Zn concentrations with respect to different hair colors, in either males or females.     

Enhanced in vitro hair growth at the air-liquid interface: minoxidil preserves the root sheath in cultured whisker follicles

Summary Inasmuch as hair follicles are difficult to maintain in culture, the study of hair biology using cultured hair follicles has met with only limited success. In our attempts to solve the problem of follicle degeneration, we cultured follicles at the air-surface interface on a modified collagen matrix (Gelfoam). In follicles cultured at the air-surface or submerged, we examined follicular morphology, hair shaft growth, sulfotransferase levels, cysteine incorporation, an expression of a tissue inhibitor of metalloproteinase (TIMP), and ultra-high sulfur keratin (UHSK). Follicles cultured at the air-liquid interface produced a 2.7-fold increase in hair growth and maintained an anagen-like morphology. Substrates such as nylon mesh seeded with fibroblasts, Full Thickness Skin?, or 5-μm polycarbonate filter also supported hair growth, whereas Gelfilm, GF-A glass filter, filter paper, or 1-μm polycarbonate filter did not. The UHSK expression was significantly higher in the air-liquid interface cultures compared to the submerged culture. Several potassium channel openers, including minoxidil, a minoxidil analog, and the pinacidil analog (P-1075), all stimulated significant cysteine incorporation in follicles. Minoxidil and its analog specifically preserved the follicular root sheath, in contrast to P-1075 which did not, indicating a difference in the two drug types. The preservation of the root sheath was measured by increased TIMP expression and sulfotransferase activity and indicates that the root sheath is a target tissue for minoxidil. Our results show that follicles cultured at the air-liquid interface maintain a better morphology and produced greater hair growth than follicles cultured on tissue culture plastic.     

Zinc,copper, and magnesium concentrations in hair of children from Southeastern Turkey

Zinc, copper, and magnesium concentrations in hair were measured in groups of children varying in one condition—protein-energy malnutrition, ricketts, thalassemia, malignancy, cardiac failure, or after prolonged infection and in healthy controls. As compared with controls, copper and magnesium concentrations were low in all groups, whereas higher values were obtained for hair zinc. These results showed that a generalized copper and magnesium deficiency were observed in the southeastern part of Turkey. However, zinc deficiency couldn’t be detected as far as the hair zinc values were concerned, although all of the subjects fell within the 50 percentile limits for their age-appropriate weights and heights.