Design, Simulation, and Fabrication of a Copper-Chrome-Based Glass Heater Integrated into a PMMA Microfluidic System.

In this paper, the development of a copper-chrome-based glass microheater and its integration into a Polymethylmethacrylate (PMMA) microfluidic system are presented. The process highlights the importance of an appropriate characterization, taking advantage of computer-simulated physical methods in the heat transfer process. The presented system architecture allows the integration for the development of a thermal flow sensor, in which the fluid flows through a 1 mm width × 1 mm length microchannel across a 5 mm width × 13 mm length heating surface. Using an electrothermal analysis, based on a simulation and design process, the surface heating behavior curve was analyzed to choose a heating reference point, primarily used to control the temperature point within the fluidic microsystem. The heater was characterized using the theory of electrical instrumentation, with a 7.22% error for the heating characterization and a 5.42% error for the power consumption, measured at 0.69 W at a temperature of 70 °C. Further tests, at a temperature of 115 °C, were used to observe the effects of the heat transfer through convection on the fluid and the heater surface for different flow rates, which can be used for the development of thermal flowmeters using the configuration presented in this work.

Oxytocin promotes functional coupling between paraventricular nucleus and both sympathetic and parasympathetic cardioregulatory nuclei.

The neuropeptide oxytocin (OXT) facilitates prosocial behavior and selective sociality. In the context of stress, OXT also can down-regulate hypothalamic-pituitary-adrenal (HPA) axis activity, leading to consideration of OXT as a potential treatment for many socioaffective disorders. However, the mechanisms through which administration of exogenous OXT modulates social behavior in stressful environmental contexts are not fully understood. Here, we investigate the hypothesis that autonomic pathways are components of the mechanisms through which OXT aids the recruitment of social resources in stressful contexts that may elicit mobilized behavioral responses. Female prairie voles (Microtus ochrogaster) underwent a stressor (walking in shallow water) following pretreatment with intraperitoneal OXT (0.25mg/kg) or OXT antagonist (OXT-A, 20mg/kg), and were allowed to recover with or without their sibling cagemate. Administration of OXT resulted in elevated OXT concentrations in plasma, but did not dampen the HPA axis response to a stressor. However, OXT, but not OXT-A, pretreatment prevented the functional coupling, usually seen in the absence of OXT, between paraventricular nucleus (PVN) activity as measured by c-Fos immunoreactivity and HPA output (i.e. corticosterone release). Furthermore, OXT pretreatment resulted in functional coupling between PVN activity and brain regions regulating both sympathetic (i.e. rostral ventrolateral medulla) and parasympathetic (i.e. dorsal vagal complex and nucleus ambiguous) branches of the autonomic nervous system. These findings suggest that OXT increases central neural control of autonomic activity, rather than strictly dampening HPA axis activity, and provides a potential mechanism through which OXT may facilitate adaptive and context-dependent behavioral and physiological responses to stressors.

[The influence of preventive programs on laboral injuries]. / Impacto de los programas preventivos de accidentes de trabajo.

OBJECTIVE: To evaluate the impact of preventive programs at enterprises affiliated to the Instituto Mexicano del Seguro Social (IMSS) during 2004. METHODS: Transversal study in 987 enterprises. VARIABLES: labor injuries (LI) of temporal disability, permanent disability and death. ANALYSIS: simple and relative frequencies, rates and Anova application to differences. RESULTS: 64.4% of the enterprises decrease LI (p < 0.04), with a decrement of 2602 LI (16%); the rate of LI per 100 workers declined from 4.19 to 3.60 (p < 0.08), with a decrease of 43,369 disability days (10.93%), which represents $8,456,955 MXP. States with larger decreases were: Queretaro (80%) p < 0.05; Sinaloa (63%) p < 0.05, and Morelos (61%) p < 0.05. Permanent incapacities diminished at 12.1%, p < 0.09; the rate of permanent disability per 1000 workers diminished from 1.37 to 1.32 and death cases increased from 42 to 49. CONCLUSIONS: the expenses on consultancy by IMSS was estimated as $9,341,955 MXP. The savings on temporal and permanent incapacities was $33,691,255 MXP with a cost containment of $19,701,310 MXP. Preventive programs are profitable, because they generate benefits to the workers, the IMSS and the enterprises.

Pleural mesothelioma in paraoccupational, environmental and occupational patients exposed to asbestos.

OBJECTIVE: To identify the characteristics of pleural mesothelioma in patients exposed to asbestos. METHODS: A transverse study in 3700 cases of lung cancer was conducted. There were identified 21 cases with mesothelioma. Age, gender, smoking history, cancer development, dissemination, cytohistochemistry, lethality and total lung capacity were studied. ANOVA test was used. RESULTS: The incidence was of 0.45/100,000 patients. Four (19%) corresponded to occupational exposure (OE), seven (33%) para-occupational (PE) and ten (48%) environmental (EE). The mean age at detection was 50 years for PE, 55 years for EE and 64 years for OE. Twenty cases were male. Thirteen patients (62%) were active cigarette smokers. The latency time in PE mesothelioma was 34.5 years, in OE 40 years, and in EE more than 40 years. In 19 (90%) cases the tumor was disseminated. Diagnosis was confirmed by cytohistochemistry. Malignant mesothelioma was reported in 19 (90%) cases. The survival period was 5 months for OE patients, 10 in PE and 16 in EE. CONCLUSIONS: There is a low incidence of malignant mesothelioma in our population. Male was the predominant group. Occupational and paraoccupational exposure predominated in patients.

[Laboral talc pneumoconiosis as a low frequency disease]. / Talcosilicosis, enfermedad laboral poco frecuente.

OBJECTIVE: To identify the association between exposition to talcum powder and talcosilicosis in a cosmetic factory. METHODS: A descriptive and prospective survey including 24 workers from the bottling and grinding areas was performed. All patients had chest roentgenography. They were separated into two groups: the first patients exposed up to a period of five years and the second with more than five years exposure. Environmental monitoring of high flow polyvinyl chloride filters and galvimetric analysis was performed. The dust analysis was performed in 12 inhaling powders, eight environmental and four in workers. A Fisher exact test was applied. RESULTS: All of the exposed workers displayed radiographic findings compatible with talcosis; 18 (75%) patients had light talcosis and 6 (25%) moderate. The Fisher test was 13.7 with a p value of 0.004. Dust analysis showed: five were reported over the maximum allowed levels corresponding to the areas of compact cosmetics grinders, powder grinders, powder dispensers and the talcum final line. The analyzed talcum powder contained more than 95% of free silica. CONCLUSIONS: The association was confirmed between the exposure and the presence of talcosis.

[Pneumoconiosis in affiliated workers have irreversible sequelae]. / Neumoconiosis en trabajadores expuestos a polvos inorgánicos.

OBJECTIVE: to analyze the frequency and importance of pneumoconiosis in affiliated workers to Instituto Mexicano del Seguro Social. MATERIAL AND METHODS: it was carried out a transverse, observational and comparative study; the behavior of the qualified pneumoconiosis was revised 1994-2004. The analyzed variables were sex, age, occupation, permanent disability and economic activity. It was carried out the analysis of absolute frequencies and rates. RESULTS: it was registered 14,827 cases; the rate for 10,000 workers oscillated from 0.48 to 2.39. The 99 % were presented in males, with 14,262 cases with permanent disability (rate: 96.89 per 100 cases of pneumoconiosis); employments with more frequency were miners, quarry workers and bricklayers. The average of permanent disability for pneumoconiosis in the period was of 11.09 to 15 %. States with a higher number of cases were Coahuila, Zacatecas and Hidalgo. Economic activities with a greater incidence were the extraction and benefit of mineral coal, graphite and metallic and non-metallic minerals. CONCLUSION: cases of pneumoconiosis have been decreasing, but even the determination of diagnosis is delayed, and due to this most workers have irreversible sequelae.

[Industrial bronchitis in workers exposed to hydroalcohol]. / Bronquitis industrial en trabajadores expuestos a hidroalcoholes.

OBJECTIVE: To identify the association between industrial bronchitis and exposure to hydroalcohol. METHODS: In a prospective study, 80 workers exposed to hydroalcohol answered a standardized questionnaire and had two spirometry tests based on the American Thorax Society (ATS) criteria, to evaluate functional capacity and predominant spirometric patterns. The test included the parameters: forced vital capacity (FVC), forced expiratory volume in one second (FEV1), the ratio FEV1/FVC, the peak expiratory flow (PEF), the forced expiratory flow 25-50 (FEF50) and the forced expiratory flow 25-75% (FEF 25%-75%). Fisher exact test was used to identify differences. An environmental sampling of hydroalcohols was done as well. RESULTS: 85 % Of workers were women and 15 % men, with respiratory symptoms as follows: 25 % with cough and expectoration, 14 % thoracic pressure feeling, 23 % dyspnea; 36 % eye, nose or throat irritation. The spirometry results were: 25 % for pulmonary normal pattern; 66 % had obstructive pattern; 3 % had restrictive patterns and 6 % mixed pattern. 25 % of workers with obstructive pattern and 10 % of normal pattern had symptoms. It was obtained an OR = 1.9 (95 % CI = 1.135-3.195; p = 0.021) for the time of exposure to hydroalcohols and the presence of industrial bronchitis. The monitoring of hydroalcohols reported: 131.1 mg/m3 for isopropyl alcohol and 438.3 mg/m3; 49 workers (61 %) had bronchitis symptoms and 58 (72 %) showed obstructive or mixed patterns in the spirometry tests. The exposure to hydroalcohols was below the limits established by the Mexican Official Norm.

Workplace accident-related finger-fracture at the Mexican Institute of Social Security. Resolution time, economic impact and sequelae.

OBJECTIVE: To identify resolution time and economic impact of occupational finger fracture with permanent disability. METHODS: A cross-sectional study was conducted in 2004; the main variables were age; sex; disability days and sequelae. The International Classification of Diseases (ICD 10) was used for the study. The analysis included frequency, exceeded disability days and estimation of cost of disabilities, pensions and direct costs. Chi square test was used to identify the differences. RESULTS: 13,410 Fractures occurred nationwide: multiple finger fractures (803); thumb fractures (1982) and other finger fractures (10,625). Days of resolution time were: 70.5 days for multiple finger fractures and 51.1 days for another finger fractures. Permanent disability partial rate of thumb fracture was 5.3/100, 15.8/100 multiple finger fractures and 5.9 fractures of other finger. The estimated cost by temporary disability in the Instituto Mexicano del Seguro Social was on $10,669,000 U.S., while permanent disability costs in cases of settlements and annual pension payments were $758,536 U.S. CONCLUSIONS: Finger-fracture is a prevalent pathology whichever needs that medical procedures are review, also identify factors that decrease resolution time and establish improve actions that create boundaries on the workers damage health. It must be considered that this condition affects enterprise' productivity and decrease the quality of life from workers.

[Malingering among workers seeking disability insurance]. / Simulación en trabajadores que solicitan pensión por invalidez laboral.

OBJECTIVE: Describe the frequency and characteristics of Mexican Social Security workers with malingering disorder that request disability pension. MATERIAL AND METHODS: Comparative survey made among 136 workers seen during 2001, which were divided into three groups: malingering workers (MW), workers without disability (WOD), and workers with disability (WWD). We administered the Z Test for scaled variables and Z2 Test for nominal variables to identify group differences RESULTS: The incidence ofmalingering was of 2.2/100,000 workers. Mean age was 41.9 +/- 10.1 years, 440 was the average number of days of labor disability; 51 (37%) workers were malingerers. 35 (26%) workers were work disabled and 50 (37%) without disability. Malingerers had higher level of schooling compared with WOD and WWD (p < 0.02); most worked at the Social Security (p < 0.05), with lower number of previous jobs (p < 0.05), presented longer work disability (p < 0.05). Depressive symptoms were not frequently noted (p < 0.025) and all had normal electroencephalogram and brain computed tomography studies. CONCLUSIONS: Malingering workers who request work disability pensions follow a particular pattern that differs from other workers that request disability assessment at the Social Security Institute of Mexico.

Simulación en trabajadores que solicitan pensión por invalidez laboral / Malingering among workers seeking disability insurance

Objetivo: Describir la frecuencia y características de los trabajadores afiliados a la Seguridad Social con trastornos de simulación que solicitan pensión por invalidez. Material y métodos: Encuesta comparativa realizada en 136 trabajadores atendidos durante 2001, en quienes se identificaron tres grupos: trabajadores simuladores (TS), trabajadores sin invalidez (TSI), y trabajadores con invalidez (TCI). Para identificar las diferencias entre grupos, se aplicó la prueba z para variables escalares, y prueba de χ2 para variables nominales. Resultados: La incidencia de simuladores fue de 2.2/100,000 trabajadores. La edad media de los trabajadores fue: 41.9 ± 10.1 años, 440 fue el promedio de días de incapacidad laboral; 51(37%) trabajadores presentaron simulación. 35(26%) trabajadores fueron invalidados para el trabajo y 50(37%) sin invalidez. Los trabajadores simuladores tienen mayor nivel de escolaridad que TSI y TCI (p < 0.02); laboran mayoritariamente en la seguridad social (p < 0.05), con menor número de empleos previos (p < 0.05), presentan incapacidad laboral de mayor duración, (p<0.05), los síntomas depresivos son infrecuentes (p < 0.025) con electroencefalograma y tomografía normales. Conclusiones: Los trabajadores simuladores que demandan pensión por invalidez para el trabajo presentan características particulares diferentes a otros trabajadores que solicitan un estado de invalidez.

OBJECTIVE: Describe the frequency and characteristics of Mexican Social Security workers with malingering disorder that request disability pension. MATERIAL AND METHODS: Comparative survey made among 136 workers seen during 2001, which were divided into three groups: malingering workers (MW), workers without disability (WOD), and workers with disability (WWD). We administered the Z Test for scaled variables and Z2 Test for nominal variables to identify group differences RESULTS: The incidence ofmalingering was of 2.2/100,000 workers. Mean age was 41.9 +/- 10.1 years, 440 was the average number of days of labor disability; 51 (37%) workers were malingerers. 35 (26%) workers were work disabled and 50 (37%) without disability. Malingerers had higher level of schooling compared with WOD and WWD (p < 0.02); most worked at the Social Security (p < 0.05), with lower number of previous jobs (p < 0.05), presented longer work disability (p < 0.05). Depressive symptoms were not frequently noted (p < 0.025) and all had normal electroencephalogram and brain computed tomography studies. CONCLUSIONS: Malingering workers who request work disability pensions follow a particular pattern that differs from other workers that request disability assessment at the Social Security Institute of Mexico.

[Hypoacusia as a result of chronic traumatic acoustic lesion in workers with affiliation to the Mexican Social Security Institute, 1992-2002]. / Hipoacusia por trauma acústico crónico en trabajadores afiliados al IMSS, 1992-2002.

INTRODUCTION: Hypoacusia by chronic acoustic trauma (HTAC) is one of the main work diseases. OBJECTIVE: to analyze the distribution and frequency of hearing loss produced by chronic acoustic trauma (HLON) in workers who attend to Mexican Social Security Institute (IMSS). Also analyze the estimated cost of permanent work disabilities. MATERIAL AND METHODS: We analyze all hearing loss cases of the workers who attend to IMSS in the period between 1992 to 2001, registered in the Subsystem of registration of work's risk in the IMSS. Measures of central tendency, odds ratio (OR) and direct costs by means were calculated. RESULTS: The HLON represents 41% (1867) of all work's disease, during the period it was observed an increase of number of cases, the average of permanent disabilities, the rate of incidence and the average of rating percentage. The cases solved through a demand showed an increase to 105% in four years. The estimate monthly cost for every worker was 277 pesos. CONCLUSIONS: The HLON represents an important problem for the IMSS causing social and economic impact. If they don't take some actions to improve the quality of chronic acoustic trauma diagnosis it will have more serious consequences.

Burnout syndrome among Mexican hospital nursery staff.

OBJECTIVE: To identify frequency and related factors to burnout syndrome in the nursing staff at a specialty hospital in the Mexican state of Guanajuato. MATERIALS AND METHODS: A prolective, analytical cross-sectional study was carried out. In 236 randomly selected nurses, a 35-item questionnaire proposed by Cyberia Shink was applied in a blind survey. Seniority, workplace, shift and kind of service, work category, age and marital status were investigated for a link with burnout syndrome. RESULTS: Mean age of nursing personnel was 33+/-11.93 years with 13+/-7.2 years of seniority; 95 (40%) workers showed emotional exhaustion, 78 (32%) felt dehumanized, 148 (63%) had lost interest in their work, and 120 (50%) reported general exhaustion. From the studied nursing personnel, 92 (39%) showed burnout syndrome-compatible data. There were statistical differences with nurses without burnout syndrome age >33 years (p=0.001), seniority (p=0.05), and workplace (p=0.05), but not with kind of medical service (p=0.36), shift (p=0.86), and work category (p=0.96). Questionnaire validity in agreement with alpha Cronbach test was 0.7496. Relation between professional attrition and work environment was r=0.738. CONCLUSIONS: The instrument can be relied upon to identify burnout syndrome and is considered as acceptable. Age, seniority, and workplace are factors linked to nursing staff with burnout syndrome-compatible data. Employers, managers, and supervisors of health care services must promote preventive actions for burnout syndrome to synchronize present work conditions in nursing staff with their biologic characteristics.

Factores de riesgo asociados a los accidentes de trabajo en la industria de la construcción del Valle de México / Risk Factors Associated with Work-Related Accidents in the Construction Industry in the Valley of Mexico

Objetivo: describir la prevalencia de accidentabilidad en la industria de la construcción, factores asociados e impacto potencial en trabajadores afiliados al Instituto Mexicano del Seguro Social (IMSS) en el Valle de México. Material y métodos: casos y controles retrospectivo de casos prevalentes. Casos: 385 trabajadores de la industria de la construcción que sufrieron y les fue dictaminado accidente de trabajo en el año de 2001. Controles: 385 trabajadores activos de la industria de la construcción sin antecedente de accidente de trabajo, pareados por sexo, puesto de trabajo, y centro de trabajo. En uno y otro grupos se exploraron características demográficas y laborales que incluyó la capacitación en el trabajo. Resultados: la prevalencia de accidentabilidad en trabajadores de la construcción: 5.5%; factores de riesgo más importantes y fracción etio lógica (FeE): grupo de edad de 16 a 20 años, OR =1.58 [IC 95%: 1.40-10.7], (p=0.001), FeE:0.36, aseguramiento eventual, OR= 3.7[IC95%: 2.16-26.45], (p= 0.001), FeE: 0.72, y falta de capacitación para el trabajo, OR=5.3[IC95%: 4.9-69.2], (p= 0.01), FeE: 0.81. Variables que no mostraron significancia fueron: salario, antigüedad en el puesto, turno y jornada de trabajo. En su conjunto, la capacitación laboral estuvo ausente en 87% de todos los trabajadores sujetos a estudio. Conclusiones: la prevalencia de accidentabilidad mantiene preponderancia en la industria de la construcción del Valle de México; los factores de riesgo identificados son potencialmente modificables donde la capacitación laboral adquiere indiscutible relevancia.

Objective: Our aim was to describe construction-industry work-related accident prevalence in, associated factors in, and potential impact on affiliated workers of the Mexican Institute of Social Security (Instituto Mexicano del Seguro Social, IMSS) in the Valley of Mexico. Materials and Methods: Prevalent cases in a retrospective case-control design. Cases: These include 385 construction-industry workers who were found to have construction work-related accidents in 2001. Controls: comprised 385 active construction-industry workers without work-related accident background paired by gender, workplace, and worksite. Results. Work-related accident prevalence in construction workers was 5.5%; most important risk factors and etiology fraction (Ef) included the following: age 16-20 years odds ratio, OR = 1.58, 95% confidence interval (95% CI) 1.40-10.7, p=0.001, Efi 0.36; eventual insurance, OR = 3.7, 95% CI, 2.16-26.45, p = 0.001), Efi 0.72, and no training for job, OR =5.3, 95% CI, 4.9-69.2, p = 0.01), Ef: 0.81. Variables not showing significance were included salary, work shift, and workday. Conclusions. Work-related accident prevalence maintains its preponderance in the Valley of Mexico construction industry; identified risk factorsare potentially modifiable, among which job training acquires unquestionable relevance.

[Risk factors associated with work-related accidents in the construction industry in the Valley of Mexico]. / Factores de riesgo asociados a los accidentes de trabajo en la industria de la construcción del Valle de México.

OBJECTIVE: Our aim was to describe construction-industry, work-related accident prevalence in, associated factors in, and potential impact on affiliated workers of the Mexican Institute of Social Security (Instituto Mexicano del Seguro Social, IMSS) in the Valley of Mexico. MATERIALS AND METHODS: Prevalent cases in a retrospective case-control design. CASES: These include 385 construction-industry workers who were found to have construction work-related accidents in 2001. Controls comprised 385 active construction-industry workers without work-related accident background paired by gender, workplace, and worksite. RESULTS: Work-related accident prevalence in construction workers was 5.5%; most important risk factors and etiology fraction (Ef) included the following: age 16-20 years odds ratio, OR = 1.58, 95% confidence interval (95% CI) 1.40-10.7, p = 0.001, Ef 0.36; eventual insurance, OR = 3.7, 95% CI, 2.16-26.45, p = 0.001), Ef, 0.72, and no training for job, OR = 5.3, 95% CI, 4.9-69.2, p = 0.01), Ef: 0.81. Variables not showing significance were included salary, work shift, and workday. CONCLUSIONS: Work-related accident prevalence maintains its preponderance in the Valley of Mexico construction industry; identified risk factors are potentially modifiable, among which job training acquires unquestionable relevance.

Disabling spondyloarthrosis risk factors in valley of Mexico workers.

BACKGROUND: The objective of this study was to describe the most prevalent physically disabling conditions for insured workers belonging to the Mexican Social Security Institute (IMSS) in the Valley of Mexico and to identify risk factors for disabling spondyloarthrosis. METHODS: Retrospective cases and prevalent controls from IMSS clinics in the Mexico City metropolitan area were studied. Eighty cases were IMSS workers reporting disability due to spondyloarthrosis; 80 controls were active workers at the same workplace and shared the economic activity of the cases. The 1995 IMSS Disability Report was reviewed. From this report congenital conditions of the musculoskeletal system, obesity, history of trauma, and sociodemographic patient characteristics were assessed. RESULTS: The most important risk factors were a history of spina bifida (odds ratio [OR] = 29.3, 95% confidence interval [95% CI] = 5.3-161; p = 0.0009), supernumerary vertebrae (OR = 21.3, 95% CI = 5.3-95; p = 0.0001), history of low back (lumbar) trauma (OR = 3.9, 95% CI = 1.9-8.3; p = 0.0004), flatfoot (OR = 11.7, 95% CI = 1.9-69, p = 0.02), and obesity (OR = 2.0, 95% CI = 1.06-4.03; p = 0.04). CONCLUSIONS: A history of congenital deformity of the musculoskeletal system, spinal column trauma, and obesity were risk factors most associated with work disability due to spondyloarthrosis.

Effect of the quality of health care on permanent inability secondary to femoral fractures due to occupational accidents

Objective. To construct and validate an indicator for evaluating the quality of care for femoral fractures, and to assess the contribution of the quality of health care as a determinant of partial permanent inability secondary to femoral fractures due to occupational accidents. Materials and methods. The study was conducted from January to December 1995 at Mexican Institute of Social Security. The instrument was designed with experts' contribution along different stages and validated using implicit criteria and factorial analysis. A case-control study was then conducted to evaluate the contribution of the quality of care to inability secondary to femoral fractures. Cases were 108 active workers with permanent inability secondary to femoral fracture; controls were 94 active workers with fractu-re of femur but no permanent inability. Logistic regression modeling was used to establish the association between quality of care and partial permanent inability, adjusting by relevant variables. Results. The ultimate indicator of quality of care consisted of the following: Timely care, pre-surgical management, surgical management, and fracture complications. A final score over 229 points meant that the worker had received good quality of care. Workers getting 229 or less points had received poor quality of care. Forty-eight (44 por ciento) cases and 66 (70 por ciento) controls received good quality of medical care. The likelihood of partial permanent inability was almost three times higher among workers given poor quality of care (OR 2.95; 95 por ciento CI 1.5 - 5.5). According to the multivariate model, predictors of partial permanent inability were: Having exposed or epiphysiary fractures, being re-submitted to surgery, having less than 90 days of rehabilitation care, and receiving deficient medical care. Conclusions. The constructed instrument was validated. The level of the quality of care received by workers is a determining factor for the generation of partial permanent inability. In workers having femoral fractures, it is important to consider timely medical care and early rehabilitation, to reduce the high incidence and prevalence of this medical problem in Mexico. The English version of this paper is available too at: http://www.insp.mx/salud/index.html

Ototoxicidad en trabajadores expuestos a disolventes orgánicos / Ototoxicity in workers exposed to organic solvents

Objetivo: describir los efectos ototóxicos que provocan diversas mezclas de disolventes orgánicos en trabajadores expuestos. Diseño: estudio observacional, descriptivo y comparativo de trabajadores activos, expuestos y no expuestos a mezclas de disolventes orgánicos. Material y métodos: 111 trabajadores de tres empresas expuestos directamente a disolventes orgánicos en las áreas de producción; y 111 de un centro hospitalario, no expuestos. Se registraron los resultados de los estudios audiométricos, los de la medición ambiental de disolventes orgánicos y de sonidos de gran magnitud en el medio ambiente laboral.Resultados: los trabajadores expuestos a disolventes orgánicos tuvieron un riesgo 12 veces mayor para alteraciones auditivas, a diferencia de los no expuestos, con una p < 0.0008 (IC95 por ciento = 1.21-84.29). La ototoxicidad se caracterizó por cortipatía bilateral. No se identificó sintomatología en ninguno de los grupos examinados. Resultados: de los trabajadores expuestos, 63 presentaron hipoacusia sensorial superficial o media, identificada a través de estudios audiométricos y con diapasón; el perfil fue característico. En los restantes no se observó daño auditivo. De los trabajadores no expuestos, cinco presentaron alteraciones auditivas ocasionadas por procesos infecciosos. Conclusión: la frecuencia de cortipatía bilateral en trabajadores expuestos laboralmente a mezclas de disolventes fue mayor que en el grupo no expuesto. El daño predominante fue hipoacusia sensorial, superficial o media.

Esguince lumbar en la industria química / Lumbar sprain in the chemical industry

Objetivo: identificar y comparar el comportamiento del esguince lumbar por accidente de trabajo en los trabajadores de la industria química y en el resto de actividades económicas. Se revisaron 97.843 casos durante 1995-1997. Se analizó: tipo de riesgo, edad, sexo, ocupación, antig³edad laboral, incapacidad temporal y permanente (IPP), causa externa, acto inseguro. El tiempo de resolución promedio por caso fue de 21 a 24 días y la tasa de incapacidad permanente parcial disminuyó de 7,2 a 5,1/1.000 esguinces lumbares de trabajo respectivamente. Hay diferencias significativas en la incidencia de casos de estas poblaciones p<0,001; así como entre los días de incapacidad por caso en los años de 1995 p<0,001; 1996 p<0,001 y 1997 p<0,001. Al analizar el puesto de ayudante general contra otros puestos de trabajo se encontraron diferencias con un RR de 2,1 (p<0,001). Los trabajadores que realizan esfuerzos físicos y movimientos vigorosos contra los que no lo realizan de las poblaciones estudiadas presentan un RR de 2,03 (p<0,001). Se concluye que las medidas preventivas y de manejo médico que se han establecido en ambas poblaciones en el período 95-97, no han generado disminución significativa de la incidencia, tiempo de evolución e incapacidad permanente parcial de este problema de salud(AU)

Esguince lumbar en la industria química / Lumbar sprain in the chemical industry

Objetivo: identificar y comparar el comportamiento del esguince lumbar por accidente de trabajo en los trabajadores de la industria química y en el resto de actividades económicas. Se revisaron 97.843 casos durante 1995-1997. Se analizó: tipo de riesgo, edad, sexo, ocupación, antigüedad laboral, incapacidad temporal y permanente (IPP), causa externa, acto inseguro. El tiempo de resolución promedio por caso fue de 21 a 24 días y la tasa de incapacidad permanente parcial disminuyó de 7,2 a 5,1/1.000 esguinces lumbares de trabajo respectivamente. Hay diferencias significativas en la incidencia de casos de estas poblaciones p<0,001; así como entre los días de incapacidad por caso en los años de 1995 p<0,001; 1996 p<0,001 y 1997 p<0,001. Al analizar el puesto de ayudante general contra otros puestos de trabajo se encontraron diferencias con un RR de 2,1 (p<0,001). Los trabajadores que realizan esfuerzos físicos y movimientos vigorosos contra los que no lo realizan de las poblaciones estudiadas presentan un RR de 2,03 (p<0,001). Se concluye que las medidas preventivas y de manejo médico que se han establecido en ambas poblaciones en el período 95-97, no han generado disminución significativa de la incidencia, tiempo de evolución e incapacidad permanente parcial de este problema de salud