Audiometric findings of printing press workers exposed to noise and organic solvents.

OBJECTIVE: To determine if exposure to organic solvents and noise is associated with audiometric results among workers from a printing press in Mexico City. DESIGN: Cross-sectional study. STUDY SAMPLE: One hundred and seventy-six male workers at a printing press in Mexico City exposed to noise and organic solvents, including xylene, and 103 non-exposed male workers as reference group. Hearing thresholds were assessed with pure-tone audiometry. RESULTS: Poorer hearing thresholds were observed among printing workers than non-exposed controls, particularly among groups with over 5 years of exposure. Hearing thresholds differences were observed in the frequencies above 500 Hz, especially in 4000 Hz in all exposure groups compared to the reference. Adjusted models for age and previous exposure to noise and organic solvents showed worse hearing thresholds as years of seniority increased -ß coefficients (95% CI): ≤5 years: 3.06 dB (0.01, 6.10); >5-10 years: 4.51 dB (1.13, 7.89); >10 years: 4.58 dB (1.20, 7.96). Further analyses showed no interaction between noise and organic solvents on hearing thresholds, considering both current and previous occupational exposures. CONCLUSION: Exposure to noise levels that were below recommended exposure limits and organic solvents were associated with poorer hearing thresholds than those observed among non-exposed study participants. This suggests that workers exposed to solvents should be included in hearing conservation programmes, even when noise exposures are below 85 dB. If only noise levels were taken into consideration in the risk assessment of this worker population, the risk of hearing effects could have been overlooked.

[Update on epidemiology, pathophysiology, diagnosis and treatment of malignant pleural mesothelioma]. / Actualización sobre la epidemiología, fisiopatología, diagnóstico y tratamiento del mesotelioma maligno pleural.

Malignant pleural mesothelioma is an occupational tumor caused by asbestos exposure. In Mexico, as asbestos usage is not prohibited, an increase in the number of cases is expected. Asbestos exposure is ubiquitous due to the great amount of products in which it is present. Its carcinogenicity is caused as the inhaled asbestos fibers cannot be eliminated by macrophages and, thus, they travel to the pleura through lymphatic pathways, producing a persistent inflammatory response. Diagnosis approach includes occupational history, along with clinical signs and symptoms, and paraclinical studies, such as pleural fluid cytology, chest x-rays, computed tomography, magnetic resonance imaging, and biopsy with immunohistochemistry. The main differential diagnosis is lung adenocarcinoma. Regarding the treatment of this tumor, it mainly comprises palliative care, even though chemotherapy, radiotherapy, and, in selected cases, surgical treatments have been used. There is an urgent need for general physicians and specialists to identify asbestos exposure, in order to make a timely diagnosis. Research is necessary to develop screening and prompt diagnostic tools, along with an epidemiological surveillance program for the workers and the general population exposed to asbestos.

El mesotelioma maligno pleural es un tumor ocupacional ocasionado por la exposición a cualquier tipo de fibra de asbesto. Y dado que en México el uso del asbesto no está prohibido, se espera que la incidencia de este tumor siga aumentando. La exposición al asbesto es ubicua, debido a la gran diversidad de productos en los que se encuentra. Su carcinogenicidad está dada porque las fibras de asbesto inhaladas no pueden ser eliminadas por los macrófagos y viajan hacia la pleura por vía linfática, donde producen una reacción inflamatoria persistente. Para su diagnóstico se precisa de una historia clínica laboral, además de que hay que orientarse con base en el cuadro clínico y los estudios paraclínicos, como la citología de líquido pleural, radiografía de tórax, tomografía axial computarizada, resonancia magnética y biopsia con inmunohistoquímica. El principal diagnóstico diferencial es el adenocarcinoma de pulmón. El tratamiento es principalmente paliativo, aunque se ha utilizado quimioterapia, radioterapia y, en seleccionados casos, cirugía. Para lograr un diagnóstico oportuno y certero es de vital importancia identificar las exposiciones al asbesto. Por otra parte, es necesaria la investigación para desarrollar pruebas de diagnóstico temprano y tamizaje, además de un programa de vigilancia epidemiológica para los trabajadores y la población general expuesta al asbesto.

[Brainstem auditory evoked potentials latencies, by age and sex, among Mexican adult population]. / Latencias de los potenciales evocados auditivos del tallo cerebral, por edad y sexo, en población adulta mexicana.

BACKGROUND: Brainstem auditory evoked potentials (BAEP) evaluate the auditory pathway, and are a complementary test for tone audiometry in evaluating auditory diseases. The aim of the study was to determine BAEP mean latencies of waves and intervals, among healthy adults. METHODS: Cross-sectional study, comprising 196 subjects, aged 16 to 65 years, without auditory diseases, to whom family and personal history were asked, physical examination and laboratory studies were made, as well as tonal audiometry, impedanciometry and BAEP. RESULTS: A total of 107 men and 89 women were studied. The mean latency periods of waves I, III and V, and intervals I-III, III-V and I-V from both ears were similar. An increase in the latency periods for each age category was observed. Latency periods were significantly shorter in women compared to men. The predictors that increased the latency periods in the multiple linear regression models for waves and intervals were male gender and age ≥45 years. CONCLUSIONS: Age and sex were the variables that showed more statistical power to explain the latencies' differences.

Introducción: los potenciales evocados auditivos del tallo cerebral (PEATC) evalúan la vía auditiva central y son una herramienta complementaria de la audiometría tonal para analizar enfermedades auditivas. El objetivo de este estudio fue determinar el tiempo promedio de las latencias de las ondas y los intervalos de los potenciales evocados auditivos en adultos sanos. Métodos: estudio transversal que contó con 196 participantes, de 16 a 65 años de edad normo-oyentes, a quienes se investigaron antecedentes familiares y personales patológicos, se realizó exploración física y se obtuvieron estudios de laboratorio, audiometría tonal e impedanciometría normales, y potenciales evocados auditivos. Resultados: Se estudiaron 107 hombres y 89 mujeres. El promedio de las latencias de las ondas I, III y V e intervalos I-III, III-V y I-V de ambos oídos fueron similares. Los predictores que incrementaron el tiempo de latencia en los modelos de regresión lineal múltiple de las ondas e intervalos fueron el sexo masculino y la edad ≥ 45 años. Conclusiones: la edad y el sexo fueron las variables que mostraron mayor poder estadístico para explicar las diferencias de las latencias en este grupo de personas.

Blood lead determinants and the prevalence of neuropsychiatric symptoms in firearm users in Mexico.

OBJECTIVES: To identify blood lead predictors and the prevalence of neuropsychiatric symptoms in firearm users of public security in Mexico. MATERIAL AND METHODS: A cross-sectional study was performed on 65 males. We obtained socio-occupational data and determined venous blood lead (blood (B), lead (Pb) - BPb), as well as neuropsychiatric symptoms using the Q-16 questionnaire. A multiple linear regression model was constructed to assess determinants of BPb. RESULTS: The mean age in the study group was 34.8 years (standard deviation (SD) = 6.9, range: 21-60); the mean number of years spent in the company amounted to 14 years (SD = 8.5, range: 1-48). Twenty percent of the respondents (N = 13) used leaded glazed clay pottery (lead (Pb), glazed (G), and clay pottery (C) - PbGC) in the kitchen. During practice they fired a mean of 72 shots (SD = 60, range: 20-250), and during their whole duration of employment 5483 shots (SD = 8322.5, range: 200-50 000). The mean BPb was 7.6 µg/dl (SD = 6.8, range: 2.7-51.7). Two caretakers from the firing range had 29.6 µg/dl and 51.7 µg/dl BPb. The subjects who had shooting practice sessions ≥ 12 times a year reported a greater percentage of miscarriages in their partners (24% vs. 0%). Twelve percent of the respondents showed an increase in neuropsychiatric symptoms. The BPb multiple linear regression model explained R2 = 44.15%, as follows: those who had ≥ 12 practice sessions per year - ß = 0.5339 and those who used PbGC - ß = 0.3651. CONCLUSIONS: Using firearms and PbGC contributes to the increased BPb in the studied personnel. The determinants of BPb were: shooting practices >12 times a year and using PbGC. Blood lead concentrations reported in the study, despite being low, are a health risk, as evidenced by the prevalence of neuropsychiatric symptoms.

Alteraciones neuropsicológicas por exposición crónica a concentraciones bajas de monóxido de carbono en trabajadores de autopista de peaje de México / Neuropsychological alterations by chronic exposure to low concentrations of carbon monoxide in highway workers of Mexico

ANTECEDENTES: Trabajadores de la industria automovilística, estaciones de servicio, autopistas de peaje, estacionamientos y los que laboran en las calles, están en contacto crónico con bajas concentraciones de monóxido de carbono (CO) y, por lo tanto, en riesgo de sufrir alteraciones en los sistemas cardiovascular, hematológico y nervioso. OBJETIVO: Identificar la relación de las alteraciones neuropsicológicas con la exposición crónica a bajas concentraciones de CO, en trabajadores de autopistas de peaje. MÉTODO: Estudio transversal en 72 trabajadores de autopistas de peaje de la carretera México-Puebla; 60 cajeros y 12 encargados de turno. Se exploraron variables socio-demográficas, clínicas y ocupacionales, y se determinó hemoglobina (Hb), hematocrito (Htc) y carboxihemoglobina (COHb) en sangre. Se aplicaron pruebas neuropsicológicas (Carbon monoxide neuropsychological screening battery CONSB). Los encargados de turno conformaron el grupo menos expuesto y los cajeros el de mayor exposición a CO. RESULTADOS: En 49 trabajadores, Hb: 18.1±1.9 mg/dL y Htc: 55.3±8.7, sin diferencias significativas entre grupos (p = 0.82). Se observó menor desempeño en el grupo más expuesto, en el test de dígitos y símbolos (p = 0.012), senderos B (p = 0.002) y dígitos (p = 0.003). El test de construcción con bloques resultó limítrofe (p = 0.07). DISCUSIÓN Y CONCLUSIÓN: El grupo de mayor exposición al CO tuvo menor desempeño en percepción visual, codificación, percepción visomotora y memoria inmediata. Por ello, consideramos importante realizar vigilancia epidemiológica en los trabajadores, para intervenir en los casos con alteraciones en las pruebas. Asimismo, se debe evitar la percepción de que la exposición crónica al CO en estos trabajadores es inocua.

BACKGROUND: Workers of the automobile industry, service stations and those working in the streets, are in chronic contact to low concentrations of carbon monoxide and at risk to damage the cardiovascular, haematology and nervous systems. OBJECTIVE: Identify erythrocytosis and neuropsychological alterations in highway workers chronically exposed to low concentrations of CO. METHOD: Cross-sectional study that included 72 workers of the Mexico-Puebla Highway cabins (guards); 60 cashiers and 12 workers in charge of the shift, in which socio-demographic, clinical and occupational variables were explored; haemoglobin(Hb), hematocrit (Htc) and carboxyhemoglobin (COHb) was determined in their blood, and it was applied the Carbon monoxide neuropsychological screening battery (CONSB). The workers who are in charge of the full shift integrated the less exposed to CO group, while the cashiers would shape the greater exposure group. RESULTS: In 49 workers, Hb: 18.1±1.9 mg/dL and Htc: 55.3±8.7 without significant differences between groups (p=0.82). The greater alteration was identified in the exposed group in the test of digit symbol (p= 0.012), trail-making part B (p= 0.002), and digit span (p=0.003); the test of blocks design resulted borderline (p=0.07). DISCUSSION AND CONCLUSIÓN: The group with the highest exposure to CO had lower performance in visual perception, encoding, visual-motor perception and immediate memory. Therefore important to consider epidemiological surveillance workers to intervene in cases with abnormal tests. The perception of innocuousness of chronic exposure to CO in these workers must avoid.

[Historical and social perspective from the 64-65 Mexican medical movement]. / Perspectiva histórica y social del Movimiento Médico de 1964-1965 en México.

The Mexican Medical Movement from 1964-1965 constitutes an important event from the rising urban middle-class, besides it was the first time medical doctors claimed for fair working conditions. The background of this movement is the so-called Crisis of 1958, which included the Movements from the educators union, oil workers union, telegraph workers union and the railroad workers union. The conflict began because interns and residents from the "Hospital 20 de Noviembre" would not get a payment at the end of the year, so on November 26th, 1964, the movement started. The Asociación Mexicana de Médicos Residentes e Internos (AMMRI) was created and their demands were the following: 1) Full working site restitution without retaliations, 2) Legal examination of the scholarship-contract terms, in order to get annual, renewable and progressive contracts, and a fixed salary with the usual working-hours and characteristics of each institution, 3) To have preference to get an adscription at the hospital where the resident studied, 4) Active participation from the resident in the elaboration of the academic plans, and 5) Resolution of each hospital's problems. This movement had social impact for Mexico's contemporary life, nevertheless some of the demands are still unchanged among medical residents.

El movimiento médico mexicano de 1964-1965 constituyó parte del primer despertar de la clase media urbana, además de haber sido la primera vez que los médicos reclamaron condiciones de trabajo justas. Como antecedente se tiene la llamada crisis de 1958, la cual incluyó los movimientos: revolucionario del Magisterio, del Sindicato de Trabajadores Petroleros, de la Alianza de Telegrafistas, y del Sindicato de Trabajadores Ferrocarrileros de la República Mexicana. El comienzo del conflicto médico se debió a que los residentes e internos del Hospital 20 de Noviembre del hoy Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE) no recibieron su aguinaldo, por lo que el 26 de noviembre de 1964 inició el paro, a partir del cual se formó la Asociación Mexicana de Médicos Residentes e Internos (AMMRI), cuyas demandas fueron: 1) Restitución total en sus puestos, sin represalias, 2) Revisión legal y cambio de los términos del contrato-beca, en el sentido de lograr contratos de trabajo anuales, renovables y progresivos, con el horario y características acostumbrados en cada institución además de determinación de sueldos base, 3) Preferencia para ocupar plaza de médico adscrito a los residentes egresados de las propias instituciones, 4) Participación activa del residente en la elaboración de los planes de enseñanza, y 5) Resolución de los problemas de cada hospital. Este movimiento, aunque tuvo repercusiones sociales para la vida contemporánea en México, a 50 años de su inicio, algunas de las demandas siguen sin ser resueltas para los médicos residentes.

[Overview of sharps injuries among health-care workers]. / Panorama de heridas por objetos punzocortantes en trabajadores intrahospitalarios.

Sharps injuries are one of the most frequent health-care related accidents. It is estimated globally that 35 million workers are at risk; in Mexico there is no data available for this type of injuries. They are associated with lack of training, instrument and procedure risk, fatigue and stress. The occupational distribution is nurses 45 %, technicians 20 %, doctors 20 % and maintenance workers 5 %. The most commonly associated procedures are injection, venipuncture, suture, and insertion and manipulation of IV catheters. Hepatitis B is the most commonly transmitted agent. Emotional distress is huge as well as the cost of prophylaxis and follow-up. More than half of the injuries are not notified. The most common reasons for not reporting are: the belief that the exposure has low risk of infection, the lack of knowledge of reporting systems and the assumption that it is difficult to notify. Many strategies have been created to reduce the incidence of sharps injuries, such as: identifying the risk of blood exposure, the creation of politics to minimize the risk, the education and training to create a safe workplace, the enhancing of the reporting system, the use of double-gloving and using safety-engineered sharps devices. In many countries these politics have reduced the incidence of sharps injuries as well as the economic burden.

Las heridas por objetos punzocortantes son uno de los accidentes intrahospitalarios más frecuentes. A nivel mundial se estima que 35 millones de trabajadores de la salud se encuentran en riesgo; en México no se tienen datos actualizados para estas heridas. Los accidentes están relacionados con falta de entrenamiento, características de los instrumentos y procedimientos, y fatiga y estrés de quien los practica. La distribución por ocupación es: enfermeras 45 %, técnicos 20 %, médicos 20 % y mantenimiento 5 %. Los procedimientos asociados son: inyección, venopunción, sutura, manipulación e inserción de catéter intravenoso. La infección más comúnmente transmitida es la hepatitis B. La afectación emocional por ansiedad es grande al igual que los costos por profilaxis y seguimiento. Más de la mitad de las heridas por punzocortantes no son notificadas. Las razones más comunes para no reportar son: la suposición de que hay bajo riesgo de infección, la falta de conocimientos sobre métodos de reporte y la creencia de que es difícil notificar. Numerosas estrategias han sido creadas para reducir la incidencia, por ejemplo: la identificación del riesgo de exposición a sangre, la creación de procesos y políticas, la educación y el entrenamiento para laborar en un ambiente seguro, asícomo alentar el reporte de accidentes, el uso de doble enguantado y la utilización de dispositivos de seguridad. En varios países, estas políticas han logrado disminuir la incidencia de heridas por punzocortantes a la vez que se ha generado un ahorro para los sistemas de salud.

Increased Cardiovascular Risk Using Atherogenic Index Measurement Among Healthcare Workers.

BACKGROUND AND AIMS: Cardiovascular diseases are one of the leading causes of death worldwide. This burden of disease is particularly high among healthcare workers. The aim of the study was to identify determinants that increase atherogenic index among healthcare workers. METHODS: In 1,678 healthcare workers, cardiovascular risk factors were analyzed: body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, glucose, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. Atherogenic index was calculated and determinants were identified. RESULTS: Mean (SD) age was 41.2 (8.4) years; body mass index 28.4 (4.8); waist-hip-ratio 0.88 (0.07); glucose 96.6 (22.2) µg/dL; TC 195.3 (50.3) mg/dL; HDL 49.0 (16.3) mg/dL; LDL 112.7 (35.0) mg/dL; triglycerides 171.7 (121.2) mg/dL; and atherogenic index 3.3 (1.5). Overweight and obesity prevalence was 77.2%. In the multiple linear regression model, the coefficients for AI were being a physician ß = 0.381, male gender = 0.443, BMI ß = 0.35, waist-to-hip ratio ß = 2.15, age = 0.014, and triglycerides ß = 0.915. CONCLUSIONS: The main contributors to atherogenic index increase were male sex, increased age, waist-to-hip ratio increase, overweight and obesity, high triglyceride levels and working as a physician. Although waist-to-hip ratio was the most powerful determinant, the physician occupational category added risk factors such as stress and adverse psychosocial working conditions, which may potentiate cardiovascular diseases.

Seroprevalence of Pandemic A(H1N1) pmd09 Virus Antibodies in Mexican Health Care Workers Before and After Vaccination.

BACKGROUND AND AIMS: In April 2009, a new strain of influenza A(H1N1) was identified in Mexico and in the U.S. In June 2009, WHO declared this a pandemic. Health care workers constituted a risk group for their close contact with infected individuals. The aim was to estimate seropositivity for A(H1N1)pdm09 in health staff at the Instituto Mexicano del Seguro Social. METHODS: A two-stage cross-sectional study, before and after vaccination in the same workers, was performed on a random sample of health-care workers. A socio-occupational questionnaire was applied and serum antibodies against influenza A(H1N1)pdm09 were determined through neutralization of retroviral pseudotypes; two logistic regression models for both were constructed. RESULTS: The average (median/mean) age of 1378 participants from 13 work centers was 41.7 years and 68.7% (947) were women. Seroprevalence for the first stage was 26.5% (365) (7.4-43%) vs. 20.8% (11) in a control group from the blood bank; for the second stage, the vaccinated group was 33% (215) (18.2-47%) and 27% (196) (11.6-50%) for the unvaccinated group. In regression models, seropositivity was associated with occupational exposure to suspected influenza infected patients, being physicians, and being vaccinated. CONCLUSIONS: Seropositivity against pandemic virus is similar to what was reported, both for vaccinated (2.8-40.9%) and unvaccinated (18.8-64.7%). Low seroprevalence in the vaccinated group indicates that between 67% and 73% were susceptible to infection. Given the relatively low vaccine-induced seropositivity, it is imperative to increase, hygiene and safety for health staff and at-risk populations, and strengthen epidemiological surveillance.

Malignant Pleural Mesothelioma: Accuracy of CT Against Immunohistochemical Test Among the Mexican Population.

BACKGROUND AND AIMS: Malignant pleural mesothelioma (MPM) is associated with occupational and environmental exposure to asbestos. The incidence is expected to increase as the use of asbestos is not prohibited in many countries, such as in Mexico. We undertook this study to determine sensitivity, specificity, predictive values and likelihood ratios of computed tomography (CT) in a sample from Mexican population with suspected MPM and other pleuropulmonary diseases. METHODS: CT films of 38 patients suspected of having MPM were analyzed. A single observer was blinded to MPM diagnoses. The frequencies of ten CT findings were identified. A cut-off point of ≥5 CT findings was established to determine high MPM probability. Sensitivity, specificity, predictive values and likelihood ratio of the CT against biopsy using immunohistochemical testing (IHC) for MPM were calculated. RESULTS: Of the 38 patients, 31 had MPM and seven had lung adenocarcinoma. The five key findings were mediastinal pleural thickening 96.7% (n = 30), nodular pleural thickening 93.3% (n = 29), pleural mass 83.9% (n = 26), diminished lung 70.9% (n = 22) and contracted hemithorax 70.9% (n = 22). Sensitivity 96.8% (83.2-99.4), specificity 85.7% (42.2-97.6), positive likelihood ratio 6.7 (1.1-41.6), and negative likelihood ratio of 0.04 (0.01-0.2) were reported. CONCLUSIONS: Sensitivity and specificity in this study was greater than previously reported, 96.8% and 85.7 vs. 93.2 and 65.6%, respectively. CT is an easily accessible and useful tool that should be incorporated into the medical education of general physicians to improve MPM diagnosis of suspected cases.

[Association between the risk of major depression and low physical activity in peruvian workers studying in universities]. / Asociación entre el riesgo de depresión mayor y el bajo nivel de actividad física en trabajadores peruanos que cursan estudios universitarios.

In order to assess if an association exists between the risk of major depression (RMD) and physical activity (PA), controlling for demographic and academic variables in workers enrolled in undergraduate studies at a private university in Lima, Peru, we carried out a cross-sectional study of 1,111 people. We used the Major Depression Inventory (MDI) and the International Physical Activity Questionnaire (IPAQ) to measure RMD and PA, respectively. RMD prevalence was 4.2%. In the multiple regression model adjusted for age, gender, unemployment and hours of sleep, low levels of PA were associated with increased odds of RDM (OR: 2.15, 95% CI: 1.16 to 4.00). We conclude that there is an association between RMD and PA in the study population, independent of demographic and academics factors. Strategies to improve screening and development of longitudinal studies to assess causality are suggested.

Asociación entre el riesgo de depresión mayor y el bajo nivel de actividad física en trabajadores peruanos que cursan estudios universitarios / Association between the risk of major depression and low physical activity in peruvian workers studying in universities

Con el objetivo de evaluar si existe asociación entre el riesgo de depresión mayor (RDM) y la actividad física (AF) controlado por variables sociodemográficas y académicas en trabajadores que cursan estudios de pregrado en una universidad privada de Lima, se desarrolló un estudio de corte transversal analítico en 1111 personas. Se utilizó el inventario de depresión mayor y el cuestionario internacional de actividad física, para medir RDM y AF, respectivamente. La prevalencia de RDM fue 4,2 %. En el modelo de regresión de múltiples variables - ajustado por edad, sexo, desempleo y horas de sueño- la AF baja se asocia con un incremento de la odds de RDM (OR 2,15; IC 95%:1,16û4,00). Se concluye que existe asociación entre la RDM y la AF en la población estudiada, la cual es independiente de factores sociodemográficos y académicos. Se sugieren mejorar estrategias de tamizaje y el desarrollo de estudios longitudinales para evaluar causalidad...

In order to assess if an association exists between the risk of major depression (RMD) and physical activity (PA), controlling for demographic and academic variables in workers enrolled in undergraduate studies at a private university in Lima, Peru, we carried out a cross-sectional study of 1,111 people. We used the Major Depression Inventory (MDI) and the International Physical Activity Questionnaire (IPAQ) to measure RMD and PA, respectively. RMD prevalence was 4.2%. In the multiple regression model adjusted for age, gender, unemployment and hours of sleep, low levels of PA were associated with increased odds of RDM (OR: 2.15, 95% CI: 1.16 to 4.00). We conclude that there is an association between RMD and PA in the study population, independent of demographic and academics factors. Strategies to improve screening and development of longitudinal studies to assess causality are suggested...

Ototoxicity effects of low exposure to solvent mixture among paint manufacturing workers.

OBJECTIVE: To evaluate auditory function in a group of workers exposed to organic solvent mixture at a paint factory. DESIGN: Cross-sectional study. STUDY SAMPLE: One hundred and sixty-one workers were studied, 77 exposed to solvents and 84 unexposed. Fourteen solvents were measured, including toluene, xylene, and n-hexane. Pure-tone audiometry and brainstem auditory-evoked potentials (BAEP) were performed. Industrial noise was < 85 dBA and exposure levels to organic solvents were low. RESULTS: The exposed group showed a hearing impairment in both ears compared with the unexposed workers. Multiple linear regression models adjusted by age, chronic pathologies, and environmental noise for frequency means between 125 and 8000 Hz produced the following results: for the left ear, R(2) = 33.3%, exposed vs. unexposed ß = 4.1 (p < 0.001); and for the right ear, R(2) = 38%, exposed vs. unexposed ß = 4.8 (p < 0.001). Adjusted for age and chronic pathologies, waves III and V, and interpeak interval latencies were increased (p < 0.05) in both ears in the exposed group. CONCLUSIONS: Although solvent mixture concentrations and noise levels were low, our results demonstrate that there may be a concurrent ototoxicity and neurotoxicity condition and emphasize the importance of including BAEP analysis for comprehensive assessments. Future studies that include otoacoustic emissions assessments to monitor cochlear function and central auditory processing tests are imperative.

[Concordance in blood lead quantification between laboratories]. / Concordancia interlaboratorios en la cuantificación de plomo en la sangre.

OBJECTIVE: To establish a blood lead quantification correlation from two occupational health laboratories (OHL1V and OHL2DF), and the ABC Hospital (LABC) metals laboratory. METHODS: A cross-sectional study was performed in 84 workers from a voltage regulators company, where lead is welded; in 54 % (46 of them) a blood sample was taken and analyzed by OHL1V, and in 28.6 % (24) by OHL2DF. All samples were analyzed by atomic absorption spectrophotometry. Pearson correlation (r), coefficient of determination (r2), Lin (rho) concordance test, and Bland-Altman plots were calculated. RESULTS: The blood lead mean: LABC was 5.8 ± 2.4 µg/dL vs. OHL2DF of 4.4 ± 3.6 µg/dL (r = 0.25 [p = 0.24], r2 = 0.06 [p = 0.24], and rho = 0.21 [p = 0.21]). And with LABC, 6.75 ± 3.3 µg/dL vs. OHL1V 5.6 ± 2.9 µg/dL (r = 0.91 [p < 0.001], r2 = 0.83 [p < 0001], and rho = 0.85 [p< 0.001]). CONCLUSIONS: Agreement between LABC and OHL1V was poor (< 0.90), and with OHL2DF was null. An occupational health laboratory certification is needed in order to have reliable biological exposure index measurements in lead occupational exposure.

OBJETIVO: determinar la concordancia de las cuantificaciones del plomo en la sangre de dos laboratorios del Instituto Mexicano del Seguro Social (LST1V y LST2DF), con las del Laboratorio de Metales del Hospital ABC (LABC). MÉTODOS: se realizó un estudio transversal en 84 trabajadores que sueldan con plomo en una empresa de reguladores. Se tomaron muestras de sangre; 100 % fue analizado por el LABC, 54 % (46) por el LST1V y 28.6 % (24) por el LST2DF. Todas las muestras se analizaron por espectrofotometría de absorción atómica. Se calculó la correlación de Pearson (r), el coeficiente de determinación (r2), la concondancia de Lino (rho) y las gráficas de Bland-Altman. RESULTADOS: las muestras analizadas en el LST2DF indicaron 4.4 ± 3.6 µg/dL de plomo en la sangre y en el LABC, 5.8 ± 2.4 µg/dL (r = 0.25 [p = 0.24], r2 = 0.06 [p = 0.24] y rho = 0.21 [p = 0.21]). Las muestras analizadas en el LST1V indicaron 5.6 ± 2.9 µg/dL y en el LABC, 6.75 ± 3.3 µg/dL (r = 0.91 [p< 0.001], r2 = 0.83 [p< 0.001] y rho = 0.85 [p< 0.001]). CONCLUSIONES: los resultados del LABC concordaron pobremente con los del LST1V (< 0.90) y no lo hicieron con los del LST1-DF. Es necesario certificar a los laboratorios institucionales y acreditar a los técnicos que realizan los análisis, para obtener resultados confiables de los indicadores biológicos de exposición ocupacional.

Panorama del subregistro de los accidentes y enfermedades de trabajo en México / Overview of the underreporting of accidents and occupational diseases in Mexico

A nivel internacional, el subregistro-al menos de los accidentes de trabajo- se ha determinado entre 33 y 69%. En México, las instancias responsables de la evaluación de este tipo de circunstancia señalan que es de alrededor del 8%, sin embargo, a partir de diversas contribuciones realizadas dentro del sistema del Instituto Mexicano del Seguro Social (IMSS), el cual solo atiende a aproximadamente el 40% de la población trabajadora del país, se han identificado cifras de entre 26 y 78% en el período 1994-2004, sin tomarse en cuenta lo que respecta a enfermedades de trabajo. Bajo esta perspectiva se advierte la necesidad de ampliar la visión y certidumbre en la atención de este problema basados en el análisis de sus causas y orígenes, para finalmente delinear posibles propuestas para su contención o eventual eliminación, con la coparticipación de las instituciones responsables de su registro veraz y de su atención médica, las instancias que emiten las normas al respecto, los empresarios, y sin lugar a dudas, de los mismos trabajadores, sus gremios y los grupos organizados que los representan.

Worldwide, the underreporting-at least of occupational accidents-has been determined from 33 to 69%. In Mexico, the instances responsible for the evaluation of these circumstances indicate that is about 8%, however, from various contributions made within the system of the Mexican Social Security Institute (IMSS), which only serves approximately 40% of the working population of the country, figures have been identified between 26 and 78% in the period 1994-2004, without taking into account the occupational diseases. Under this perspective, may proceed broaden the vision and certainty in the attention of this problem based on the analysis of its causes and origins, and finally to outline possible proposals for its containment or eventual elimination, with the participation of the institutions responsible for accurate registration and medical care, instances that emit norms about the issue, the employers, and certainly, the workers themselves, their unions and the organized groups that represent them.

La equidad y la salud en el trabajo: explorando un área emergente / Inequity and health in the workplace: exploring an emergent area

El trabajo, bajo condiciones de empleo justo y decente, reduce las inequidades en salud; sin embargo, en la actualidad parece prevalecer la obtención y desempeño de este sin los atributos referidos, con exposición tanto a accidentes como a padecer enfermedades causadas por diversos agentes, y a riesgos ergonómicos y psicosociales presentes en el trabajo, y los relacionados con el modo de trabajar impuesto por el wildmarket y sin prestaciones en materia de seguridad social. Las políticas que en salud y seguridad en el trabajo deberían instituir los países miembros de la Organización Internacional del Trabajo (OIT) acortarían las inequidades mencionadas, no obstante, el Estado, quien garantizaría esas políticas, parece haberse convertido en intermediador a favor de los grandes corporativos. Es fundamental que se definan y fortalezcan acciones para constituir empleos con condiciones apropiadas y decorosas, a fin de generar equidad, igualdad y bienestar social.

Work, under fair employment and decent work, reduces inequities in health. Nowadays it seems, however, that obtaining and carrying out a job and worker performance take precedence over the aforementioned attributes. Workers are not only exposed to accidents, diseases caused by various agents, ergonomic and psychosocial risks but also affected by work modes imposed by the “wildmarket”, such as the lack of social security benefits. Member countries of the International Labour Organization (ILO) should institute occupational health and safety policies in order to reduce the above mentioned inequities. Nonetheless, governments, which would guarantee such policies, seem to have become intermediaries in favor of large corporations. It is essential to define and strengthen actions that create jobsin decent and appropriate conditions with a view to generating equity, equality, and social well-being.

Perfil salud-enfermedad en los trabajadores de una empresa en el valle de México / Profile healt-disease in a company workers in the valley of Mexico

Introducción: Los estudios de salud en el trabajo, abordan puntualmente algún efecto adverso a la salud de los trabajadores. El objetivo es, determinar el perfil salud-enfermedad de los trabajadores de una empresa. Material y métodos: Se realizó un estudio transversal al 90% del personal. Se utilizó el Programa para la Evaluación y el Seguimiento de la Salud de los Trabajadores, para determinar el perfil salud enfermedad y determinar algunos de sus predictores. Resultados: Se estudiaron a 121 trabajadores. En los trabajadores del almacén, son mayores los riesgos y las exigencias laborales (83%) y las patologías estudiadas (52%). Los síntomas psicosomáticos se incrementan por: ser vendedor b=2.91, con el índice de riesgos y exigencias b=0.11; disminuyen cuando el salario es suficienteb=-2.98, y por contar con otro trabajo b=-2.66 (p<0.05; R2=13%). La presión arterial sistólica se incrementa por la edad b=0.33, ser administrativo b=9.1 y vendedor b=10.03; y disminuye por ser mujer b=-8.0 (p<0.05;R2=17%). La presión arterial diastólica se incrementa con la edad b=0.234, por ser administrativo b=3.14 y vendedor b=4.5 (p=0.050; R2=9.5%). Y para los trastornos mentales, sólo el índice de riesgo b=0.050 (p=0.051;R2=7%). Discusión y conclusiones: Los vendedores y administrativos presentan incremento en los síntomas psicosomáticos y tensión arterial; a pesar de reportar menos riesgos y exigencias, con relación a los almacenistas. La satisfacción salarial y tener otro trabajo, disminuyen los síntomas psicosomáticos en estos trabajadores (AU)

Introduction: Occupational health studies promptly address some adverse effect on workers health. The aim was to determine the health-disease profile of workers in a company. Material and Methods: A cross-sectional study was performed on 90% of the staff. Program for the Evaluation and Monitoring of Workers Health was used to determine the health-disease profile and to determine some of its predictors. Results: 121 workers were studied. Greater risks and job demands (83%), and pathologies studied (52%) are present in warehouse workers. Psychosomatic symptoms are increased in salesmen b=2.91, with risks and job demand index b=0.11; these decrease when wage is sufficient b=-2.98, and having another job b=-2.66 (p<0.05;R2=13%) Systolic blood pressure increases with age b=0.33, be administrative b= 9.1 and salesman b=10.03, and decreases being woman b=-8.0 (p<0.05, R2=17%). Diastolic blood pressure increases with age b=0.234, being administrative b=3.14, and salesman b=4.5 (p=0.050, R2=9.5%) And for mental disorders, only the risk indexb=0.050 (p=0.051, R2=7%) Discussion and conclusions: Salesmen and administrative staff exhibit psychosomatic symptoms and arterial blood pressure increases despite reporting fewer risks and job demands in relation to warehouse workers. Pay satisfaction and have another job decreases psychosomatic symptoms in these workers (AU)

[Male hormonal profile in workers exposed to toluene in an industrial packaging plant]. / Perfil hormonal masculino de trabajadores expuestos a tolueno en una fábrica de empaques industriales.

OBJECTIVE: to identify changes in the male hormonal profile (MHP), consisting of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone, in workers exposed to toluene. METHODS: cross-sectional study that included 42 workers, formed in two groups: with high and low exposure to toluene (HET and LET, respectively); the hippuric acid in urine, and the serum concentration in FSH, LH, and testosterone were measured. RESULTS: hippuric acid in subjects with LET was 2.53 ± 1.20 g/g creatinine, and with HET: 6.31 ± 3.83 g/g creatinine (p = 0.02). Seric FSH concentration was 5.12 ± 0.77 and 3.55 ± 0.3 mU/mL (p = 0.02) in LET and HET, respectively; LH: 2.66 ± 0.45 and 2.77 ± 0.21 (p = 0.81), and testosterone 3.91 ± 0.34 and 4.86 ± 0.23 ng/mL (p = 0.04). By regression analysis, the correlation coefficient of FSH with hippuric acid was r = -0.33 (p = 0.031), with coefficient of determination of 11 %; the LH correlation coefficient was r = -0.037 (p = 0.88) and 0.05 %, respectively; and the one for testosterone was r = 0.61 (p = 0.0001) and 34 %. CONCLUSIONS: in HET group, FSH and LH serum levels diminished; testosterone shows an opposite response, perhaps explained by a different sensitivity of the male gonads exposed to toluene.

Objetivo: identificar cambios en el perfil hormonal masculino (PHM), integrado por las hormonas luteinizante (LH), folículo-estimulante (FSH) y testosterona, de trabajadores expuestos a tolueno. Métodos: estudio transversal que incluyó a 42 trabajadores. Se constituyeron dos grupos: con exposición alta (EAT) y con exposición baja (EBT) a tolueno. Se midió la concentración sérica de FSH, LH y testosterona, así como el ácido hipúrico en orina. Resultados: ácido hipúrico en sujetos con EBT: 2.53 ± 1.20 g/g creatinina; con EAT: 6.31 ± 3.83 g/g creatinina (p = 0.02). Concentración sérica de FSH: 5.12 ± 0.77 y 3.55 ± 0.3 mU/mL (p = 0.02) en EBT y EAT, respectivamente; de LH: 2.66 ± 0.45 y 2.77 ± 0.21 (p = 0.81); y testosterona: 3.91 ± 0.34 y 4.86 ± 0.23 ng/mL (p = 0.04). Por análisis de regresión, el coeficiente de correlación de FSH con ácido hipúrico fue de r = -0.33 (p = 0.031), con coeficiente de determinación de 11%; el de LH: r = -0.037 (p = 0.88) y 0.05 % respectivamente, y el de testosterona: r = 0.61 (p = 0.0001) y 34 %. Conclusiones: en el grupo EAT, los niveles séricos de la FSH y LH disminuyeron; la testosterona muestra una respuesta contraria, lo cual quizás se explique por una diferente sensibilidad de gónadas masculinas a la exposición del tolueno.

[Inequity and health in the workplace: exploring an emergent area]. / La equidad y la salud en el trabajo: explorando un área emergente.

Work, under fair employment and decent work, reduces inequities in health. Nowadays it seems, however, that obtaining and carrying out a job and worker performance take precedence over the aforementioned attributes. Workers are not only exposed to accidents, diseases caused by various agents, ergonomic and psychosocial risks but also affected by work modes imposed by the "wildmarket", such as the lack of social security benefits. Member countries of the International Labour Organization (ILO) should institute occupational health and safety policies in order to reduce the above mentioned inequities. Nonetheless, governments, which would guarantee such policies, seem to have become intermediaries in favor of large corporations. It is essential to define and strengthen actions that create jobs in decent and appropriate conditions with a view to generating equity, equality, and social well-being.

[Blood disorders among workers exposed to a mixture of benzene-toluene-xylene (BTX) in a paint factory]. / Alteraciones hematológicas en trabajadores expuestos ocupacionalmente a mezcla de benceno- tolueno-xileno (BTX) en una fábrica de pinturas.

OBJECTIVES: Evaluate the three blood cell series and identify the presence of hypochromia, macrocytosis, leucopenia, lymphopenia, and thrombocytopenia in a group of workers exposed to the mixture of benzene-toluene-xylene (BTX). MATERIALS AND METHODS: A cross-sectional study which included 97 workers from a paint factory in Mexico. The participants underwent conventional blood count and tests for potential cumulative daily dose of BTX fumes, to estimate exposure. RESULTS: From the total of workers, 19.6% showed macrocytosis, 18.6%, lymphopenia, hypochromia 10.3%, 7.2% and 5.2% thrombocytopenia leukopenia. The crude association of macrocytosis with exposure to high doses of BTX mixture was the only with statistical significance (OR: 3.6, 95% CI 1.08 to 13.9, P = 0.02), and the base for a logistic regression model (OR: 6.7, 95% CI 1.33 to 13.55, P = 0.02) adjusted for age, alcohol consumption, and smoking. CONCLUSIONS: All blood cytological components analyzed demonstrated mild changes, potentially associated with exposure to the mixture of BTX. Macrocytosis could constitute an early manifestation worthy for surveillance.