Urinary Mutagenicity in Chemical Laboratory Workers Exposed to Solvents

Solvents represent an important group of environmental pollutants to which people are exposed daily in the workplace. The physico chemical properties of solvents may result in disturbances to cellular structures, including damage to DNA. However, the effects of mixtures of solvents are not well known. Mutations caused by environmental agents are related to cancer development and other degenerative diseases. The work in a research laboratory that uses several types of solvents is equally predisposed to these hazards. In this study, we evaluated the mutagenicity of urine from 29 subjects exposed occupationally to solvents in a chemistry research laboratory and 29 subjects without occupational exposure (controls). Urine samples were collected in polyethylene containers at the end of the work shift. For the concentration and extraction of urine samples the XAD-2 resin was used with acetone as an eluting agent. Several strains of Salmonella typhimurium (TA100, TA98, TA97a, TA1535, YG1024) should be used to assess mutagenic susceptibilities among workers exposed to organic solvents. Different doses of extract (1.5; 3.0; 6.0 and 12.0 m/ equivalents of urine per plate) were tested on S. typhimurium strains TA100 and YG 1024, with and without metabolic activation. The mutagenic activity, measured in Salmonella typhimurium YGI1024 with S9 mix, was significantly greater in urine from workers than from controls (p <= 0.05). These results indicate the relevance of using biomarkers to assess the risk of occupational exposure to organic solvents.

Mutagenic activity of sweepings and pigments from a household-wax factory assayed with Salmonella typhimurium

The mutagenic activity of garbage originating from a household wax industry was determined by the Salmonella/microsome assay, using the bacterial strains TA100, TA98 and YG1024. The garbage was obtained by sweeping the floor of the factory at the end of the work shift. Organic compounds were extracted by ultrasound for 30 min in dichloromethane or 70% ethanol. After evaporation of solvent, these extracts (HFS: household-wax factory sweepings) were dissolved in DMSO, and were tested for the mutagenic activity at varying concentrations (HFS-ET: 0.08-0.68 mg/plate, HFS-DCM: 0.60-7.31 mg/plate). The colouring agents (pigments) used in the production of the wax were also dissolved in DMSO and tested with the assay. The concentrations tested for each pigment were: Amaranth: 0.46-3.65 mg/plate, Auramine: 0.15-1.2 mg/plate, Tartrazine: 0.46-3.65 mg/plate and Rhodamine B: 0.22-1.82 mg/plate. Both ET and DCM organic extracts had mutagenic activity, especially in the YG1024 strain. The pigments behaved in a similar way, demonstrating that YG1024 was the most sensitive strain for the detection of mutagenicity, and that metabolization increased the activity. Human exposure (occupational and non-occupational) to industrial residues generated during the household-wax manufacturing and packaging process should be monitored, since this type of garbage is normally deposited in the environment without any control. (C) 2004 Elsevier Ltd. All rights reserved.

Mutagenic activity in waste from an aluminum products factory in Salmonella/microsome assay

The mutagenic activity of waste material originating from an aluminum products factory was determined by the Salmonella/microsome assay, using the bacterial strains TA100, TA98 and YG1024. The material was obtained by sweeping the factory floor at the end of the work shift. Organic compounds were extracted by ultrasound for 30 min in dichloromethane or 70% ethanol. After evaporation of solvent, these extracts were dissolved in dimethylsulfoxide, and tested for the mutagenic activity at varying concentrations. All the extracts from the factory had mutagenic activity, especially in the YG1024 strain, suggesting the presence of aromatic amines, later confirmed by chemical analysis. The TA98 strain also showed mutagenic activity, though it did not exhibit the highest mutagenicity index observed with the YG1024 strain. In TA100, mutagenic activity was not observed. This study should serve as an alert to management and those who are occupationally exposed, and as a warning that this type of waste should not be discarded in the environment without any control. (C) 2004 Elsevier Ltd. All rights reserved.

Occupational exposure to paint solvents and particulate material in car repair shops

Aims: We evaluated solvents and total particulates exposures in auto body repair shops together with a search of painter's related complaints. Methods: 26 painters exposures were evaluated by pumped personal sampling; solvents were retained in charcoal sorbent tubes and the particulates in PVC filters. Painter's personal habits and their work characteristics were obtained through a questionnaire, applied in a private interview. For the symptoms the Q16 questionnaire was used, added of questions about complaints during the painting. Results: High exposures were detected during spray painting. For solvents, the TLV-STEL adjusted for the mixtures was surpassed in six evaluations. However, as repaint is a short-term operation, it makes the average concentrations weighed for the work shift lower than the TLV-TWA adjusted for the mixtures. Total particulate concentrations had surpassed the TLV-TWA in four of the evaluations. Symptoms frequency in the Q16 questionnaire was higher for painters than for the controls (Mann-Whitney test U=193; p=0.008), and they showed positive correlations with the age (Spearman r=0.354, t=1.85, p=0.076), the number of years in the profession (Spearman r=0.433, t=2.35, p=0.027) and the alcoholic beverage consumption (Spearman r=0.457, t=2.516, p=0.019). Conclusions: The painting work done at car repair shops can result in high solvent and particulate exposures, although they are short-term operations. Their acute and chronic effects for the painters do not have been clearly evidenced in the present study, continuing deserving multidisciplinary attention.

Electromyographic analysis of masseter and anterior temporalis muscle in sleep bruxers after occlusal splint wearing

Bruxism is widely defined as an anxiety response to environmental stress. Occlusal splints are frequently used in sleep bruxism, to protect teeth from damage resulting from the contraction force of mandibular muscles, or to reduce the orofacial pain by relaxing masticatory muscles. Surface electromyography (EMG) of the right and left masseter and temporalis muscles was performed in 15 women presenting sleep bruxism and temporomandibular disorders related to occupational stress, after nocturnal use of the occlusal splint. The EMG signals were recorded twice per patient: After a work shift (pre-splint) and after a night of sleep with the occlusal splint (post-splint) before a new workday. The parametric t-paired test was used to compare differences of the RMS amplitude between pre and post-splint records, for resting and maximal clenching effort. The level of significance for each comparison was set to p < 0.05. The results of the study supports the premise that the use of occlusal splint reduces EMG activity in the masseter and anterior temporalis muscles, in patients who presented with sleep bruxism related to occupational stress. © 2011 Elsevier Ltd.

Análise da mutagenecidade urinária e susceptibilidade genética no monitoramento de indivíduos expostos a solventes orgânicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cleaning Conveyor Belts in the Chicken-Cutting Area of a Poultry Processing Plant with 45 degrees C Water

Conveyor belts are widely used in food handling areas, especially in poultry processing plants. Because they are in direct contact with food and it is a requirement of the Brazilian health authority, conveyor belts are required to be continuously cleaned with hot water under pressure. The use of water in this procedure has been questioned based on the hypothesis that water may further disseminate microorganisms but not effectively reduce the organic material on the surface. Moreover, reducing the use of water in processing may contribute to a reduction in costs and emission of effluents. However, no consistent evidence in support of removing water during conveyor belt cleaning has been reported. Therefore, the objective of the present study was to compare the bacterial counts on conveyor belts that were or were not continuously cleaned with hot water under pressure. Superficial samples from conveyor belts (cleaned or not cleaned) were collected at three different times during operation (T1, after the preoperational cleaning [5 a.m.]; T2, after the first work shift [4 p.m.]; and T3, after the second work shift [1:30 a.m.]) in a poultry meat processing facility, and the samples were subjected to mesophilic and enterobacterial counts. For Enterobacteriaceae, no significant differences were observed between the conveyor belts, independent of the time of sampling or the cleaning process. No significant differences were observed between the counts of mesophilic bacteria at the distinct times of sampling on the conveyor belt that had not been subjected to continuous cleaning with water at 45 degrees C. When comparing similar periods of sampling, no significant differences were observed between the mesophilic counts obtained from the conveyor belts that were or were not subjected to continuous cleaning with water at 45 degrees C. Continuous cleaning with water did not significantly reduce microorganism counts, suggesting the possibility of discarding this procedure in chicken processing.

O sertão literário na contemporaneidade: Guimarães Rosa e Ronaldo Correia de Brito

The text analyses the way in which regionalism, centered in the representation of social and human relations and related to universalism, has been applied to Guimarães Rosa and the way in which it appears nowadays in the work of Ronaldo Correia de Brito. This aim is pursued by means of reflections on the survival of the expression regionalism, its application to the work of Guimarães Rosa – especially in one composition of Tutameia – and its contemporary reappearance in a short story by Correia de Brito.

O trabalho docente na rede pública do estado de São Paulo: apontamentos iniciais para a discussão da jornada de trabalho

The changes in the world of work that, in turn, directly affect the teaching work, have expanded the processes of precariousness and intensification, contributing for deteriorating conditions which teachers use to labor. Considering that the time designated for teaching activities is an important part of work conditions, we look for, in this article, to analyze the work shift of teachers in São Paulo state educational public system. Regarding that teachers are a very heterogeneous group, we have chosen to discuss the workday those professionals who dedicate themselves in the last years of elementary and high school. Through a literature review and a research about the legislation related to the topic, in Brazil and São Paulo state, we have highlighted that the teachers’ work shifts should include not only the time for classroom activities, but also for other extra activities. Moreover, we emphasize that the state of São Paulo government has promoted, since 2012, a reformulation of the teachers’ work shift that has not properly include the appropriate length of time for extra educational activities, contrasting the parameters founded in the national legislation. Besides the legal non-compliance, that fact has accentuated the process of intensification of teaching work, contributing for the embrittlement of the collective activities.

Administrative rationality and coping strategies in shift work

Shift work (SW) can affect worker health and productivity. Working at night, workers often accumulate fatigue and are less productive. In Brazil, laws have been drafted aiming to reduce night work and rotating shift hours. In order to slash costs, companies have been looking for new arrangements to improve productivity under these conditions. The purpose of this study was to examine management changes and their outcomes in a large glass factory located in an industrial region of Brazil. The results show that the management, seeking equal productivity among shifts, focused its efforts mainly on distributing employee expertise. The arrangement resulted in 12 different groups that combine to serve three fixed shifts. A same shift can be served by more than one group, and the members of a same group share days off on different days. There was no statistically significant productivity difference among the three shifts. The on-site examination showed that part of the production was held by the workers and transferred to the next shift in order for them to be able to meet the management's performance rate requirements. The finding shows how a Brazilian cultural trait (resistance without conflict) is used to drive coping in SW.

Sleep, ageing and night work

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sleep complaints and polysomnographic findings: A study of nuclear power plant shift workers

The literature widely recognizes that shift workers have more health complaints than the general population. The objective of this study was to describe the prevalence of sleep complaints and verify the polysomnographic (PSG) variables of shift workers in two Brazilian nuclear power plants. We carried out a subjective evaluation with a sleep questionnaire. Based on these results, the interviewees that reported sleep-related complaints were referred for polysomnographic evaluation. of the 327 volunteers initially evaluated by the sleep questionnaire, 113 (35%) reported sleep complaints; they were significantly older, had higher body mass index (BMI), and worked more years on shifts than those without sleep complaints. of these 113, 90 met criteria for various sleep disorders: 30 (9%) showed obstructive sleep apnea (OSA), 18 (5.5%) showed limb movement, and 42 (13%) evidenced both sleep problems and had a significantly higher proportion of sleep stage 1 and arousals compared with the 23 shift workers that had no indices of sleep problems. The present study found that 90 (27.5%) of the evaluated participants met the PSG criteria of some type of clinical sleep disorder. This high proportion should be investigated for associations with other aspects of work, such as working hours, working schedule, years performing shift work, and access to health services. Due to the strong association between sleep disorders and the incidence of fatigue and sleepiness, the evaluation of the sleep patterns and complaints of shift workers is essential and should be considered to be one of the basic strategies of industry to prevent accidents.

Sistemas dinâmicos finitos: Paciência Búlgara (Shift em partições e composições cíclicas)

Pós-graduação em Matemática - IBILCE

Do Circadian Preferences Influence the Sleep Patterns of Night Shift Drivers?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)