Organophosphate (OP) poisoning is a progressively worrying phenomenon as worldwide pesticide production and consumption has doubled. On average, WHO estimates that 3% of agricultural workers in developing Asian countries suffer an episode of pesticide poisoning every year. Furthermore, the threat of OP usage in terrorism is existent, as seen by the subway tragedy in Tokyo in 1995 where sarin was used. Despite these alarming facts, there is currently no global system to track poisonings related to pesticide use. Human serum paraoxonase (PON1) is the enzyme that hydrolyses OP compounds. Serum PON1 levels and activity vary widely among different ethnic populations. Two commonly studied polymorphisms of PON1 are PON1Q192R and PON1L55M. PON1R192 hydrolyses paraoxon faster than PON1Q192 but hydrolyses diazoxon, sarin and soman eight times slower, and vice versa. PON1M55 has lower plasma levels of PON1 than PON1L55. As the prevalence of the different alleles and genotypic distribution vary between the Asian populations we studied, we propose the necessity to study PON1 polymorphisms and its role in OP toxicity in Asian populations. This would help safeguard the proper care of agricultural workers who might be affected by OP poisoning, and alert relevant anti biological terrorism agencies on possible risks involved in the event of an OP attack and provide effective counter measures.
This study was initiated to evaluate o-cresol and benzylmercapturic acid in urine in comparison with other biomarkers, as tools to estimate the intensity of occupational exposure to toluene at low levels. In total, 108 solvent exposed workers (engaged in tape production) and 17 non-exposed controls (all men) participated in the study. The surveys were conducted in the second half of working weeks. Diffusive sampling was conducted to measure 8-h time-weighted average intensity of occupational exposure to toluene. Blood and urine samples were collected at the end of a working shift. Blood samples were subjected to analysis for toluene (Tol-B), and urine samples were analyzed for benzyl alcohol (BeOH-U), benzylmercapturic acid (BMA-U), o-cresol (o-CR-U), hippuric acid (HA-U) and toluene (Tol-U) by the methods previously described. The toluene concentrations in workplaces were low in general, with a geometric mean (GM) and the maximum concentration of 1.9 ppm and 8.8 ppm, respectively. The statistical analyses of the six biomarkers for correlation with air-borne toluene showed that both Tol-B and Tol-U gave a high correlation coefficient of 0.58 to 0.61 (p<0.01), whereas the coefficients for BeOH-U and BMA-U together with HA-U were all low (up to 0.22, depending on the correction for urine density) and statistically insignificant (p>0.10) in most cases. o-CR-U had an intermediary coefficient of 0.20 (p<0.05). Comparison with previous publications disclosed that BeOH-U, BMA-U and HA-U correlate with toluene in air when the exposure is intense (e.g., 50 ppm or above), but no longer proportional to air-borne toluene when the exposure is low, e.g., 2 ppm. Such appeared to be also the case for o-CR-U. In over-all evaluation, the validity of o-CR-U in monitoring occupational exposure to toluene at low levels (e.g., 2 ppm) appear to be limited, and BMA-U is not an appropriate biomarker. BeOH-U and HA-U are also inappropriate for this purpose. Only Tol-B and Tol-U may be employed to estimate toluene exposure at low levels.
Burnout of nurses at university hospitals was analyzed in relation to their personality characteristics and coping behaviors. A self-administered questionnaire regarding burnout (the Copenhagen Burnout Inventory), work-related stressors (the Nursing Job Stressor Scale), personality characteristics (Short-Form Eysenck Personality Questionnaire-Revised), and coping behaviors (the short Japanese version of Brief COPE) was used. We obtained answers from 778 nurses (response rate: 94.9%), and analyzed 707 female registered nurses. Multiple regression analysis showed that neuroticism was more closely related to personal, work-related, and client-related burnout than extroversion. Covariate structure analysis revealed that among the nurses with high neuroticism and low extroversion, client-related burnout was found to be correlated with stressors in relation to conflict with patients and with positive coping behaviors. Among the nurses with low neuroticism and high extroversion, client-related burnout correlated with the coping behavior of behavioral disengagement and conflict with patients. In both groups, an increase in quantitative workload was associated with a higher score for stressors arising from conflict with patients, leading to client-related burnout. These results suggest that acquisition of skills to cultivate appropriate coping behaviors might be useful for reducing client-related burnout in relation to nurses' personality characteristics. These findings need to be further endorsed by intervention studies.
To investigate the effects of acupuncture on perceived pain, mood disturbances and medical expenses related to low back pain (LBP), an intervention study was performed among 72 employees of a steel company, 70 males and 2 females, aged 53.1±7.1 (mean±SD) yr, with LBP. They received acupuncture treatment once a week for 8 wk (from October to December 1998) by licensed acupuncturists, adopting a new hypothesis of the Meridian test. Perceived pain scale, and Profile of Mood States (POMS) were administered. Past and present histories of employees' visits to hospitals and their medical expenses for LBP were surveyed from receipts obtained from the subjects' branch factory and from receipts from another nearby branch factory (control) during the period from April 1998 to March 1999. After 8 wk of treatment, patients with LBP reported diminished pain (p<0.01). POMS showed a significant decrease in the total mood disturbance score (p<0.001). The number of visits to conventional hospitals (12.1±8.0 vs. 0.8±0.8 per month, p<0.05) and standardized medical expenses for LBP (100.1±89.6 vs. 7.3±6.9 per month, p<0.05) after acupuncture intervention (November 1998 to March 1999) were significantly decreased as compared with those before intervention (April 1998 to October 1998). In contrast, such decreases were not observed in employees from the control branch factory. It is suggested that acupuncture can reduce medical expenses for LBP through improvement in mood and pain.
White blood cell (WBC) count is well known to be an independent risk marker for cardiovascular disease. The aim of this study is to examine the relationships of WBC counts to seven health practices including obesity, eating habits, smoking, alcohol intake, sleeping, physical activity, and perceived mental stress, and then clustering the relevant healthy practices. The subjects were 1,492 male and 316 female Japanese workers aged 40 yr and over in 2002. Each of seven health practices from a self-administered questionnaire was categorized as a ‘healthy’ or ‘unhealthy’ practice, and WBC counts from fasting blood samples were determined by automated particle counters. The means of age and WBC counts were 49.5 yr and 5,375 cells/μl in men, and 48.6 yr and 4,890 cells/μl in women, respectively. After multivariate adjustments for all health practices and age, the estimated WBC counts were significantly lower in normal weight subjects and never or former smokers (p<0.01). Age-adjusted WBC counts decreased significantly by 204.9±23.7 cells/μl (means±SE) and 117.6±53.2 cells/μl for each increase in one healthy practice (p<0.05), respectively, suggesting that cultivating healthier practices would lead to lower WBC counts. This study recommends modifying unhealthy practice one by one and maintaining healthy practices as an effective strategy for the prevention of atherosclerotic diseases, in addition, to quit smoking or abstain from heavy smoking especially in men is important to prevent the low-grade inflammation.
The present study investigated the effects of 1-bromopropane (1BP) on brain neuroactive substances of rats to determine the extent of its toxicity to the central nervous system (CNS). We measured the changes in neurotransmitters (acetylcholine, catecholamine, serotonin and amino acids) and their metabolites or precursors in eight brain regions after inhalation exposure to 1BP at 50 to 1,000 ppm for 8 h per day for 7 d per week for 3 wk. Rats were sacrificed at 2 h (Case 1), or at 19 h (Case 2) after the end of exposure. In Case 1, the level of 5-hydroxyindoleacetic acid (5HIAA) was lowered in some brain regions by 1BP exposure. The decrease of 5HIAA in the frontal cortex was statistically significant at 50 ppm 1BP exposure. In Case 2, γ-amino butyric acid (GABA) and taurine were decreased in many brain regions of exposed rats, and a significant decrease of taurine in the midbrain occurred at 50 ppm 1BP exposure. In both cases of 2-h and 19-h intervals from the end of exposure to sacrifice, aspartate and glutamine levels were elevated in many brain regions, but the acetylcholine level did not change in any brain region. Three-week repeated exposure to 1BP produced significantly changes in amino acid contents of rat brains, particularly at 1,000 ppm.
To clarify the association between heat stress, physiological responses and subjective workload evaluations in kitchens using an induction heating stove (IH stove) or gas stove. The study design was an experimental trial involving 12 young men. The trial measured ambient dry-bulb temperature, globe temperature, wet-bulb globe temperature (WBGT) and relative humidity; the subjects' weight, heart rate, blood pressure, oxygen uptake, amount of activity, body temperature, subjective awareness of heat and workload before and after mock cooking for 30 min. The IH stove insignificantly increased heat indicators in the work environment and workers showed lower oxygen uptake, skin temperature, subjective awareness of heat and workload after heat exposure. Both physiological load and subjective awareness of heat and workload were slight in kitchens using the IH stove, which provided a better work environment.
This article describes the second phase of a large study of Lithuanian dentists' health, and focuses on self-reported physical health complaints, general health state and associations between the two. In 2006, a postal questionnaire survey of all (N=2,449) licensed dentists registered with the Lithuanian Dental Association was conducted, obtaining a response rate of 68.2%. Fatigue (94.7%) and back pain (91.0%) were the most prevalent physical complaints reported, and they were also the most likely to become chronic among all physical disorders. Hypertension, joint diseases and allergy were the most prevalent diagnosed and treated diseases during the previous 12 months. Only half of the surveyed Lithuanian dentists (50.4%) rated their health as satisfactory. Logistic regression revealed that fatigue (Odds Ratio: 0.52; 95%CI: 0.29-0.94), headache (OR: 0.62; 95%CI: 0.42-0.90), hand problems (OR: 0.62; 95%CI: 0.44-0.87), chest pain (OR: 0.51; 95%CI: 0.40-0.64) and musculoskeletal complaints (OR: 0.41; 95%CI: 0.28-0.60) had a significant negative impact on dentists' self-reported general health. Overall, this study suggests that Lithuanian dentists do experience a certain amount of occupationally-related health problems. It is therefore important to increase health knowledge on occupational hazards and also to emphasize the importance of early diagnosis and treatment for these disorders in Lithuania, as elsewhere.
Research on occupational accidents on construction sites in Turkey is very few. Moreover, research on motor vehicle and equipment accidents also do not exist. Investigation in the scope of this study shows that after falls and contact with electricity, accidents involving heavy equipment and motor vehicles rank third and fourth, respectively. This study aims to reveal the characteristics of these types of accidents, deduct the prominent causes that lead to fatalities as well as permanent disabilities using the present data. With the aid of obtained results, recommendations are made for safety experts on how to derive data from insufficient sources in Turkey and to evaluate these data for prevention and mitigation of the risks that construction workers are exposed to. 168 fatal and 38 non-fatal traffic accident-caused incidents as well as 206 fatal and 97 non-fatal construction equipment accidents, which were selected from official statistics and expert reports, were taken into consideration. Analysis and classification of these accidents were done according to the way they happened, the type of construction site and the occupation of the victims. Moreover, the leading causes of fatal and non-fatal injuries, to which drivers, operators and co-operators are exposed, are presented. Critical findings concerning prominent ways of occurrence, type of construction work and occupation are presented; and a number of measures for reducing the present risks are suggested. Some approaches for analysing relevant data are proposed for further research.
Vitamin C is an essential micronutrient maintaining the state of well being of individuals. This study examined factors affecting and the blood vitamin C levels of motorized tricycle drivers in Parañaque City, Philippines. Consenting drivers (N=49) were included in the study and were assessed through self-administered questionnaires, 24-h food recalls, and anthropometric measurements and on the analysis of their blood vitamin C levels. Factors related to the blood vitamin C levels of the motorized tricycle drivers were determined by correlation analysis. Majority (79.6%) of drivers had low blood vitamin C levels. Workplace and vitamin C supplementations (p<0.05) were significantly related to the blood vitamin C levels of the motorized tricycle drivers. Further studies are recommended to understand the problem and the determinants of vitamin C deficiency among the general population.
The aim of this study was to investigate the effect of individual training of workers, using an instrument to quantitatively evaluate the noise attenuation gained with the use of earplugs, on the efforts to promote the use of hearing protection devices. The subjects were 68 male workers exposed to noise of above 80 dBA at an electronic parts manufacturer in Japan. They received group instruction on the prevention of noise-induced hearing loss, and individual education on the effect of the proper use of earplugs. The individual education was done with the use of an instrument that measures the noise attenuation effect of wearing earplugs. After the training, the prevalence of the regular use of hearing protectors increased. Among workers in loud working environments, it increased from 46% to 66% over two months after the training. The percentage of workers who obtained a sufficient noise attenuation effect of≥25 dB in both ears with the proper use of earplugs also increased, from 46% before the training to 72% immediately afterward. These effects were still observed about two months after the intervention. The results suggest that the present individual training may be an effective means to increase both the usage rate and the proper use of hearing protection devices, perhaps because it deepens individuals' understanding of the effect of the proper use of such devices.
We report findings regarding otolaryngologist-confirmed rhinitis, current exposure to MWF aerosols, fungi, and endotoxins for workers in a plant manufacturing automobile piston rings. Questionnaire data showed that 61.5% of 187 workers exhibited rhinitis-related symptoms. Rhinitis was confirmed in 99 of 115 workers whom were medically examined. Otolaryngologist-confirmed rhinitis was present in 10 of 19 grinding workers (52.6%), 67 of 142 production workers (47.2%), and 22 of 26 quality control (QC) workers (84.6%). These rates are much higher than the rates of rhinitis-related symptoms in automobile plants and other occupational settings and quite high even allowing for the common occurrence of rhinitis in the general population. We found that rhinitis could develop even in workers exposed to less than 0.5mg/m3 MWF aerosol. The average exposure to fungi exceeded 10 × 103 CFU/m3, a level higher than that reported for other automobile plants. Although we were unable to identify significant risk factors for rhinitis using only the physician-confirmed rhinitis cases, this study concludes that exposure to MWF aerosol, which would include microbes and metals, could contribute to a high occurrence of rhinitis in grinding and production workers. Forty-nine workers (63.6%) of 77 rhinitis patients in grinding and production operations were determined to handle synthetic MWF directly. For QC workers, for whom the prevalence of physician-confirmed rhinitis was highest, exposure to a low level of MWF aerosol, including specific microbe species we couldn't identify, bright light, dry air, and certain work characteristics during inspection are possible risk factors for development of rhinitis. Further studies including identification of fungi species should be conducted so a firm conclusion can be made regarding the development of rhinitis in QC manufacturing plant workers.
The purpose of this study is to describe the personal exposure to respirable dust and quartz and in stone crushing units located at west of Iran. A size of 40 personal samples and 40 stationary samples were obtained and analysis was done by X-ray diffraction (XRD). The results of personal sampling were shown the concentrations of respirable dust exposure level in workers of process, hopper and drivers were 1.90, 2.22, 1.41 times greater than Occupational Safety and Health Administration permissible exposure limit (OSHA PEL). The average value of total dust and respirable dust emission from stationary sources was 9.46 mg/m3, 1.24 mg/m3 respectively, showing that 13.8 % of total dust is respirable. The efficiency of local exhaust ventilation (LEV) to control of particles inside of industrial units was greater than 99%. It is concluded from this research the particulate generated from stone crushing activities contain a significant amount of respirable particle. The amount of free silica in stone quartz is 85 to 97 percent that emission of particles effect to health workers. LEV has important effect in the removal of silica particles in stone crushing units. The worker of hoppers still exposed to silica more than standard limits.
It is possible that electromagnetic field (EMF) generated by mobile phones (MP) may have an influence on the autonomic nervous system (ANS) and modulates the function of circulatory system. The aim of the study was to estimate the influence of the call with a mobile phone on heart rate variability (HRV) in young healthy people. The time and frequency domain HRV analyses were performed to assess the changes in sympathovagal balance in a group of 32 healthy students with normal electrocardiogram (ECG) and echocardiogram at rest. The frequency domain variables were computed: ultra low frequency (ULF) power, very low frequency (VLF) power, low frequency (LF) power, high frequency (HF) power and LF/HF ratio was determined. ECG Holter monitoring was recorded in standardized conditions: from 08:00 to 09:00 in the morning in a sitting position, within 20 min periods: before the telephone call (period I), during the call with use of mobile phone (period II), and after the telephone call (period III). During 20 min call with a mobile phone time domain parameters such as standard deviation of all normal sinus RR intervals (SDNN [ms] - period I: 73.94±25.02, period II: 91.63±35.99, period III: 75.06±27.62; I-II: p<0.05, II-III: p<0.05) and standard deviation of the averaged normal sinus RR intervals for all 5-mm segments (SDANN [ms] - period I: 47.78±22.69, period II: 60.72±27.55, period III: 47.12±23.21; I-II: p<0.05, II-III: p<0.05) were significantly increased. As well as very low frequency (VLF [ms2] - period I: 456.62±214.13, period II: 566.84±216.99, period III: 477.43±203.94; I-II: p<0.05), low frequency (LF [ms2] - period I: 607.97±201.33, period II: 758.28±307.90, period III: 627.09±220.33; I-II: p<0.01, II-III: p<0.05) and high frequency (HF [ms2] - period I: 538.44±290.63, period II: 730.31±445.78, period III: 590.94±301.64; I-II: p<0.05) components were the highest and the LF/HF ratio (period I: 1.48±0.38, period II: 1.16±0.35, period III: 1.46±0.40; I-II: p<0.05, II-III: p<0.05) was the lowest during a call with a mobile phone. The tone of the parasympathetic system measured indirectly by analysis of heart rate variability was increased while sympathetic tone was lowered during the call with use of a mobile phone. It was shown that the call with a mobile phone may change the autonomic balance in healthy subjects. Changes in heart rate variability during the call with a mobile phone could be affected by electromagnetic field but the influence of speaking cannot be excluded.