ABSTRACT
Methylphenidate (MPD) is one of the most prescribed pharmacological agents, which is also used for cognitive enhancement and recreational purposes. The objective of this study was to investigate the repetitive dose-response effects of MPD on circadian rhythm of locomotor activity pattern of female WKY rats. The hypothesis is that a change in the circadian activity pattern indicates a long-lasting effect of the drug. Four animal groups (saline control, 0.6, 2.5, and 10.0 mg/kg MPD dose groups) were housed in a sound-controlled room at 12:12 light/dark cycle. All received saline injections on experimental day 1 (ED 1). On EDs 2-7, the control group received saline injection; the other groups received 0.6, 2.5, or 10.0 mg/kg MPD, respectively. On ED 8-10, injections were withheld. On ED 11, each group received the same dose as EDs 2-7. Hourly histograms and cosine statistical analyses calculating the acrophase (Ï), amplitude (A), and MESOR (M) were applied to assess the 24-h circadian activity pattern. The 0.6 and 2.5 mg/kg MPD groups exhibited significant (p < 0.05) change in their circadian activity pattern on ED 11. The 10.0 mg/kg MPD group exhibited tolerance on ED 11 and also a significant change in activity pattern on ED 8 compared to ED 1, consistent with withdrawal behavior (p < 0.007). In conclusion, chronic MPD administration alters circadian locomotor activity of adult female WKY rats and confirms that chronic MPD use elicits long-lasting effects.
Subject(s)
Central Nervous System Stimulants/pharmacology , Circadian Rhythm/drug effects , Methylphenidate/pharmacology , Motor Activity/drug effects , Animals , Dose-Response Relationship, Drug , Female , Rats , Rats, Inbred WKY , Time FactorsABSTRACT
OBJECTIVES: Potential gains in life expectancy (PGLEs) that give proper consideration to competing risks are an effective indicator for measuring the impact of multiple causes of death on a defined population. This study aimed to assess PGLE by hypothetically reducing the major causes of death in the USA from 2001 to 2008. STUDY DESIGN: PGLEs due to the reduction and elimination of heart disease, cancer, Alzheimer's disease, kidney disease or human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) were calculated by age, gender and race. METHODS: Age-specific mortality rates for the above diseases from the National Center for Health Statistics were used, and multiple decremental life tables were constructed to compute the corresponding PGLEs. RESULTS: PGLEs due to the elimination of heart disease, cancer or HIV/AIDS decreased from 2001 to 2008, but PGLEs due to the elimination of Alzheimer's disease or kidney disease increased over time. For heart disease, PGLE in 2001-2008 for all races was 2.78-2.15 for females vs 2.41-2.06 for males. For cancer, PGLE in 2001-2008 for all races was 2.97-2.81 for females vs 3.02-2.85 for males. HIV/AIDS has a greater impact on people of working age, whereas Alzheimer's disease has a greater impact on the elderly population. To compare the impacts of these diseases on life expectancy, partial multiple decremental life tables were constructed, and PGLEs were computed by a partial reduction or complete elimination of various causes of death for the entire life span as well as for certain working ages. CONCLUSION: This study outlined a picture of how each category of diseases could affect life expectancy in the US population by age, race or sex. The findings may assist in evaluating current public health improvements, and also provide useful information for directing future research and disease control programmes.
Subject(s)
Alzheimer Disease/mortality , HIV Infections/mortality , Heart Diseases/mortality , Kidney Diseases/mortality , Life Expectancy/trends , Neoplasms/mortality , Adolescent , Adult , Black or African American/statistics & numerical data , Age Distribution , Aged , Alzheimer Disease/ethnology , Cause of Death/trends , Child , Child, Preschool , Female , HIV Infections/ethnology , Heart Diseases/ethnology , Humans , Infant , Infant, Newborn , Kidney Diseases/ethnology , Life Expectancy/ethnology , Male , Middle Aged , Neoplasms/ethnology , Sex Distribution , United States/epidemiology , White People/statistics & numerical data , Young AdultABSTRACT
Circadian pattern of activity regulates many aspects of mammalian physiology and behavior to particular times of the day by entraining the circadian clocks to external environmental signals. Since circadian rhythms are sensitive to many pharmacological agents, it is important to understand if the repetitive use of psychostimulants such as amphetamine will alter the circadian rhythm behavioral activity pattern. The present study uses male Sprague-Dawley rats to study the long-term effects of amphetamine on the locomotor circadian rhythm activity pattern. Rats were randomly assigned to a testing cage that recorded their locomotor activity nonstop for eleven days using the open field assay, as follows: one day of baseline activity was recorded and then the experimental group was injected with amphetamine (0.6mg/kg) for 6days, no treatment for 3days (i.e., washout days) and then re-challenged with amphetamine for one more day while the control group was treated similarly with saline. The Cosine Curve Statistical Analysis (CCSA) test was used to fit a 24-hour curve to activity pattern. Results indicate that repetitive daily amphetamine injections cause behavioral sensitization and a significant change of circadian rhythm of locomotor activity pattern, and elicit behavioral expectation to receive the drug or expression of withdrawal during the washout days. The results suggest that either changes in circadian rhythm caused sensitization and withdrawal or sensitization and withdrawal caused the change in circadian rhythm activity.
Subject(s)
Amphetamine/pharmacology , Central Nervous System Stimulants/pharmacology , Circadian Rhythm/drug effects , Motor Activity/drug effects , Animals , Animals, Newborn , Dose-Response Relationship, Drug , Male , Random Allocation , Rats , Rats, Sprague-Dawley , Time FactorsABSTRACT
Overeating in industrial societies is a significant problem, linked to an increasing incidence of overweight and obesity, and the resultant adverse health consequences. We advance the hypothesis that a possible explanation for overeating is that processed foods with high concentrations of sugar and other refined sweeteners, refined carbohydrates, fat, salt, and caffeine are addictive substances. Therefore, many people lose control over their ability to regulate their consumption of such foods. The loss of control over these foods could account for the global epidemic of obesity and other metabolic disorders. We assert that overeating can be described as an addiction to refined foods that conforms to the DSM-IV criteria for substance use disorders. To examine the hypothesis, we relied on experience with self-identified refined foods addicts, as well as critical reading of the literature on obesity, eating behavior, and drug addiction. Reports by self-identified food addicts illustrate behaviors that conform to the 7 DSM-IV criteria for substance use disorders. The literature also supports use of the DSM-IV criteria to describe overeating as a substance use disorder. The observational and empirical data strengthen the hypothesis that certain refined food consumption behaviors meet the criteria for substance use disorders, not unlike tobacco and alcohol. This hypothesis could lead to a new diagnostic category, as well as therapeutic approaches to changing overeating behaviors.
Subject(s)
Feeding and Eating Disorders , Food , Substance-Related Disorders , Diagnostic and Statistical Manual of Mental Disorders , Humans , Obesity/epidemiologyABSTRACT
The Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates that in 2004, there were 39.4 million people living with HIV/AIDS worldwide (UNAIDS/WHO Report on the global HIV/AIDS epidemic, 2004). Children less than 15 years of age comprise 2.2 million of these individuals. As more children globally gain access to highly active antiretroviral therapy (HAART), more children are growing to the age when disclosure of their HIV status is inevitable. This information may affect a child's disease trajectory, and in the context of HAART, may have wide-ranging impact in the management of paediatric HIV infection. This study is an investigation of the effect of disclosure of a child's own HIV infection status on death and CD4 decline in a cohort of 325 HIV-infected Romanian children receiving highly active antiretroviral therapy (HAART). A retrospective database analysis was conducted. Data from a nearly three-year period were examined. Children who were aware of their HIV diagnosis were compared with those who were not aware. We found significant associations between not knowing the HIV diagnosis and death, and not knowing the HIV diagnosis and disease progression defined as either death or CD4 decline. Our results imply that in the context of HAART, knowledge of one's own HIV infection status is associated with delayed HIV disease progression.
Subject(s)
Antiretroviral Therapy, Highly Active , HIV Infections/psychology , Truth Disclosure , Adolescent , Antiretroviral Therapy, Highly Active/mortality , Antiretroviral Therapy, Highly Active/psychology , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/immunology , Child , Child, Preschool , Cohort Studies , Disease Progression , Female , HIV Infections/drug therapy , HIV Infections/mortality , Health Status , Humans , Male , Romania/epidemiologyABSTRACT
AIMS: To explore the relation between occupational and organisational factors and work related injuries (WRI) among public hospital employees in Costa Rica. METHODS: A cross-sectional survey was conducted among a stratified random sample of 1000 employees from 10 of the 29 public hospitals in Costa Rica. A previously validated, self-administered questionnaire which included occupational and organisational factors and sociodemographic variables was used. From the final eligible sample (n = 859), a total of 842 (response rate 98%) questionnaires were returned; 475 workers were analysed after excluding not-at-risk workers and incomplete questionnaires. WRI were computed for the past six months. RESULTS: Workers exposed to chemicals (RR = 1.36) and physical hazards (RR = 1.26) had higher WRI rate ratios than non-exposed workers. Employees reporting job tasks that interfered with safety practices (RR = 1.46), and a lack of safety training (RR = 1.41) had higher WRI rate ratios than their counterparts. Low levels of safety climate (RR = 1.51) and safety practices (RR = 1.27) were individually associated with an increased risk of WRI. Also, when evaluated jointly, low levels of both safety climate and safety practices showed the highest association with WRI (RR = 1.92). CONCLUSIONS: When evaluated independently, most of the occupational exposures and organisational factors investigated were significantly correlated with an increased injury risk. As expected, some of these associations disappeared when evaluated jointly. Exposure to chemical and physical hazards, lack of safety training, and low levels of safety climate and safety practices remained significant risk factors for WRI. These results will be important to consider in developing future prevention interventions in this setting.
Subject(s)
Occupational Diseases/epidemiology , Personnel, Hospital/statistics & numerical data , Wounds and Injuries/epidemiology , Adult , Costa Rica/epidemiology , Cross-Sectional Studies , Equipment and Supplies, Hospital/adverse effects , Female , Hazardous Substances/adverse effects , Hospitals, Public/organization & administration , Humans , Male , Occupational Diseases/etiology , Occupational Exposure/adverse effects , Personnel, Hospital/education , Population Surveillance/methods , Prevalence , Professional-Patient Relations , Risk Factors , Safety/standards , Wounds and Injuries/etiologyABSTRACT
Very little published research describes employer compliance with EPA-mandated Worker Protection Standard (WPS) pesticide safety training and the OSHA Field Sanitation Standard among farmworker women in general and mothers specifically. A goal of both standards is limiting farmworkers' exposure to potentially hazardous agricultural pesticides. Data from a NIOSH-supported cohort study ("Injury and Illness Surveillance in Migrant Farmworker Families") allowed for examining these issues. The cohort included 267 migrant farmworker families who usually reside along the Texas-Mexico border (Starr County, Texas). Data were collected in Starr County during in-home interviews. Of 102 mothers who participated in migrant farm work during summer 2001, 57 (55.9%) reported having ever received training/instruction in the safe use of pesticides, while 47 (46.1%) reported having received training within the previous five years, as required by WPS. Of trained mothers, 91.5% to 93.6% reported that their training covered key WPS areas: (1) entry into a recently treated field, (2) pesticide related injuries/illnesses, and (3) where to go and who to contact for emergency care following exposure. Regarding access to field sanitation, 67.5% to 84.2% of 77 mothers who worked outside Texas reported employer-provided decontamination supplies (e.g., soap, wash water, towels, and toilet facilities). However, a strikingly smaller proportion (12% to 28%) of 25 mothers who worked within Texas reported access to the same resources, suggesting discrepancies in compliance across the U.S. Due to the low level of employer compliance with both WPS and OSHA mandated standards, increased enforcement and an alternate delivery of pesticide training is recommended.
Subject(s)
Agricultural Workers' Diseases/prevention & control , Hygiene , Mothers , Occupational Exposure/prevention & control , Pesticides/toxicity , Transients and Migrants/statistics & numerical data , Accident Prevention/methods , Adult , Agricultural Workers' Diseases/chemically induced , Agricultural Workers' Diseases/epidemiology , Cohort Studies , Female , Hispanic or Latino/statistics & numerical data , Humans , Middle Aged , Occupational Exposure/statistics & numerical data , Occupational Health , Prospective Studies , Safety , TexasABSTRACT
The search for signalling systems regulating development of noradrenergic and cholinergic sympathetic neurons is a classical problem of developmental neuroscience. While an essential role of bone morphogenetic proteins for induction of noradrenergic properties is firmly established, factors involved in the development of cholinergic traits in vivo are still enigmatic. Previous studies have shown that the c-ret receptor and cholinergic properties are coexpressed in chick sympathetic neurons. Using in situ hybridization we show now that a loss-of-function mutation of the c-ret receptor in mice dramatically reduces numbers of cells positive for choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter (VAChT) in stellate ganglia of homozygous newborn animals. The number of neurons positive for tyrosine hydroxylase (TH) mRNA, the rate-limiting enzyme of noradrenaline synthesis, is reduced to a smaller degree and expression levels are not detectably altered. Already at embryonic day 16 (E16), ChAT and VAChT-positive cells are affected by the c-ret mutation. At E14, however, ChAT and VAChT mRNAs are detectable at low levels and no difference is observed between wildtype and mutant mice. Our data suggest that c-ret signalling is necessary for the maturation of cholinergic sympathetic neurons but dispensable for de novo induction of ChAT and VAChT expression.
Subject(s)
Acetylcholine/metabolism , Gene Expression Regulation, Developmental , Membrane Transport Proteins , Neurons/metabolism , Proto-Oncogene Proteins/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Sympathetic Nervous System/cytology , Age Factors , Analysis of Variance , Animals , Animals, Newborn , Cell Count/methods , Choline O-Acetyltransferase/metabolism , Embryo, Mammalian , Immunohistochemistry/methods , In Situ Hybridization/methods , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins c-ret , RNA, Messenger/metabolism , Receptor Protein-Tyrosine Kinases/genetics , Stellate Ganglion/embryology , Stellate Ganglion/growth & development , Stellate Ganglion/metabolism , Sympathetic Nervous System/embryology , Tyrosine 3-Monooxygenase/genetics , Tyrosine 3-Monooxygenase/metabolism , Vesicular Acetylcholine Transport Proteins , Vesicular Transport Proteins/metabolismABSTRACT
BACKGROUND: Specialized methods are necessary to collect data from migrant farmworkers for epidemiologic research. METHODS: We developed a questionnaire that collected lifetime occupational histories and other lifestyle risk factors via a life events/icon calendar, and administered the questionnaire to a convenience sample of 162 migrant farmworkers in nine areas of the U.S. RESULTS: The average duration of the interviews was about 1 h 30 min, with an average of 45 min for the work history section. The occupational histories covered a median of 27.6 years per person for men and 20.8 years per person for women. The median number of years spent in farm jobs was 11.3 for men and 5.8 for women. The median number of farm jobs (crop/task combination) per person was 59 among men and 27 among women. Many farmworkers performed the same crop/task combinations at multiple times throughout their lives, yielding a median of 13 unique farm jobs and 8 unique crops among men and 7 jobs and 5 crops among women. CONCLUSIONS: The project demonstrated that it is feasible to collect detailed work histories and other risk factor data from farmworkers, documented the complexity of work histories encountered among farmworkers, and yielded recommendations for refining a questionnaire that will facilitate future epidemiologic research on farmworkers.
Subject(s)
Agriculture/statistics & numerical data , Employment/statistics & numerical data , Epidemiologic Research Design , Surveys and Questionnaires , Transients and Migrants/statistics & numerical data , Adolescent , Adult , Aged , Feasibility Studies , Female , Hispanic or Latino/statistics & numerical data , Humans , Life Style , Male , Mental Recall , Middle Aged , Pilot Projects , Risk Factors , United StatesABSTRACT
BACKGROUND: Migrant and seasonal farmworkers have a high potential for pesticide exposures, yet are rarely included in epidemiologic studies. This study examined the feasibility of assessing prenatal exposures to pesticides and other compounds in pregnant Hispanic farmworkers. METHODS: Nine women completed a survey about work experiences during pregnancy. Maternal urine, cord blood, and placenta samples were obtained at delivery for analysis of 51 analytes, including 6 phenoxy acid or triazine herbicides, 21 organochlorine insecticides, 10 PCBs, and 14 volatile organic compounds. RESULTS: Seven of 51 analytes were found in the biological samples. DDE, DDT, dichlorbenzene, toluene, trimethylbenzene, and endosulfan sulfate were detected in cord blood samples, and 2,4-D in urine from one or more women. CONCLUSIONS: We documented the feasibility of following farmworkers to assess in utero exposure to pesticides and other contaminants, and demonstrated exposure to these compounds. Difficulties in measuring pesticides with short half lives were noted.
Subject(s)
Agriculture/statistics & numerical data , Maternal Exposure/statistics & numerical data , Pesticides/blood , Pregnancy/blood , Transients and Migrants/statistics & numerical data , Adolescent , Adult , Feasibility Studies , Female , Fetal Blood/chemistry , Hispanic or Latino , Humans , Pilot Projects , Surveys and Questionnaires , TexasABSTRACT
BACKGROUND: In response to The National Cancer Institute (NCI) concerns about the ability to conduct studies among migrant farmworkers, this study evaluated the feasibility of identifying migrant farmworkers in their home state and tracing them over an extended period of time. METHODS: In 1995, a group of 196 persons who had classified themselves as "migrant farmworkers" in two earlier chronic disease studies was identified. The primary objective of the current study was to determine the proportion of these farmworkers who could be located in 1995-1996. RESULTS: Of these farmworkers, 163 were located and were living (83.2%), 15 had died (7.6%), and 18 (9.2%) were lost to follow-up. CONCLUSIONS: The excellent follow-up rate was due in part to the high participation rates among persons contacted for information, stability of the farmworkers' permanent homes, predictable timing of migration, and a longstanding health research program with established community contacts.
Subject(s)
Agriculture/statistics & numerical data , Population Surveillance/methods , Transients and Migrants/statistics & numerical data , Adult , Aged , Feasibility Studies , Female , Follow-Up Studies , Hispanic or Latino/statistics & numerical data , Humans , Longitudinal Studies , Male , Middle Aged , Mortality , Population Dynamics , Surveys and Questionnaires , Texas/epidemiology , Time Factors , WorkforceABSTRACT
The identification of host factors that are predictors of changes in serum polyhalogenated biphenyl contaminants over time has been a difficult challenge in epidemiologic studies of exposed individuals. Of particular concern are age at exposure, reproductive and lactational histories, and changes in body mass index. Using both cross-sectional and longitudinal approaches, this study examined factors related to high initial serum PBB and PCB levels and changes in these levels over time among women of varying ages at exposure (n=1772; age range<1 to 45 years). In 1973, PBB exposure occurred through consumption of farm products contaminated with PBB added to cattle feed. Exposures to PCBs began in 1941 through PCB-contaminated silo sealant deteriorating into animal feed. The Michigan Department of Public Health began enrolling participants in 1977 and has continued to follow them through annual updates. At enrollment, questionnaires were administered to obtain demographic, lifestyle, and anthropometric measurements, medical/reproductive and occupational histories, and contaminated food consumption patterns. Blood samples were collected for PBB and PCB analysis at enrollment for all participants; additional serum tests were done on a subset of the population during follow-up. Median serum levels at enrollment were 2.0 ppb PBB and 5.0 ppb PCB. A decline in serum PBB level over an interval that ranged from 1 to 146 months (median=31) was observed for 44.6% of the women (median=1.0 ppb), while 12.2% showed an increase (median=1.0 ppb). PCB levels declined in 50.3% of the women (median=3.0 ppb) while 12.2% increased (median=2.0 ppb). Relative to women whose contaminant levels were stable, higher initial serum level was a predictor of decline for both PBB and PCB (OR=1.66, 95% CI 1.52-1.82; OR=3.26, 95% CI 2.58-4.12, respectively); a yearly increase in interval between tests was related to declining PCBs (OR=1.65, 95% CI 1.46-1.87). In addition, age< or =10 years at exposure (OR=1.72, 95% CI 1.03-2.86) and residence on a quarantined farm (OR=1.40, 95- CI 1.03-1.90) were predictors of a decrease in PBBs. Factors related to an increase in PBB levels were age< or =10 years at exposure (OR=0.30, 95% CI 0.10-0.96) and initial PBB level (OR=1.24, 95% CI 1.15-1.33); and for PCBs, high initial level (OR=1.34, 95% CI 1.17-1.53) and body mass index (OR=1.07, 95% CI 1.01-1.13). One or more live births during the interval between tests were not related to changing levels of either contaminant; breastfeeding data were not available for examination. Early age at exposure appears to be an important predictor of changes in serum PBB levels over time.
Subject(s)
Environmental Exposure , Environmental Pollutants/blood , Food Contamination , Polybrominated Biphenyls/blood , Polychlorinated Biphenyls/blood , Adolescent , Adult , Age Factors , Body Mass Index , Child , Child, Preschool , Cohort Studies , Cross-Sectional Studies , Demography , Female , Humans , Infant , Infant, Newborn , Life Style , Middle Aged , Odds Ratio , ParityABSTRACT
Sick Building Syndrome remains a prevalent problem with patient complaints similar to typical allergy symptoms. Unlike household allergens typically found in domestic reservoirs, the allergen from a common fungus like Aspergillus fumigatus (i.e., Asp f 1) is conceivably widespread in the work environment. This project surveyed airborne levels of the Asp f 1 allergen in office and non-industrial occupational environments, as well as the dust reservoirs of A. fumigatus believed to be responsible for those levels. Airborne and bulk dust samples were collected, extracted, and assayed for Asp f 1. Concurrently, bulk dusts collected from the same locations were selectively cultured for A. fumigatus, and mesophilic fungi and bacteria. Samples were collected during both wet and dry climatological conditions from paired wet and dry building locations to examine the possibility of Asp f 1 increases due to fungal growth blooms. Very low levels of Asp f 1 were detected but only in the airborne samples (2/120 positive samples, with 3.6 ng/m3 and 1.8 ng/m3; LOD < 1.2 ng/m3). No dust samples showed even detectable traces of the allergen (LOD = 5 ng/g dust). Although A. fumigatus counts from dusts fluctuated significantly with exterior moisture events, analysis of wet versus dry period samples showed no differences in Asp f 1 levels. These results indicate that even in the presence of measurable fungal concentrations, background levels of Asp f 1 are low. Nonindustrial office buildings devoid of indoor air quality issues were not observed to have significant levels of the Asp f 1 allergen in the geographical region studied.
Subject(s)
Air Pollutants, Occupational/analysis , Aspergillus fumigatus/isolation & purification , Dust/analysis , Sick Building Syndrome/microbiology , Colony Count, Microbial , Humans , Humidity , Sick Building Syndrome/prevention & control , TexasABSTRACT
The purpose of this study was to determine whether the occurrence of accidental blood-borne pathogen exposure incidents in medical students and residents in training varies during the 24 h. A retrospective review of reported exposures was conducted in a large urban teaching institution--the University of Texas Health Science Center in Houston--between November 1993 and July 1998. Professional level (year of student or level of resident), time of exposure, means/route of exposure (needle stick, laceration, or splash), and type of medical service were recorded. Analysis of the clock time of the 745 reported blood-borne pathogen exposures showed they occurred more frequently during the day than night. Over the nearly 5-year span, 531 incidents took place between 06:00 and 17:59 in comparison to only 214 between 18:00 and 05:59. To account for the day-night difference in medical student and resident hospital staffing, the data were reexpressed as exposure rates, that is, in terms of the number of events per hour per 1000 medical students and residents. Based on the total number of reported exposures over the almost 5-year span of data collection, the average rate was 40 accidents per hour per 1000 doctors in training during the 12 h daytime span (6:00-17:59). It was 50% greater at night (18:00-05:59), with 60 incidents per hour per 1000 doctors in training. The day-night difference in rate of exposures was statistically significant (p < .04). The relative risk ratio for residents and students when working during the day shift compared to working the night shift was 0.67. This means that doctors in training are at a 1.50 higher risk of sustaining a blood-borne pathogen exposure when working nights than when working days.
Subject(s)
Blood/microbiology , Circadian Rhythm , Internship and Residency , Needlestick Injuries/epidemiology , Students, Medical , Adult , Blood/parasitology , Blood/virology , Female , Humans , Male , Occupational Diseases/epidemiology , Retrospective Studies , Skin/injuries , Texas/epidemiologyABSTRACT
In response to growing concern for occupational health and safety in the public hospital system in Costa Rica, a cross-sectional survey of 1,000 hospital-based health care workers was conducted in 1997 to collect baseline data that are being used to develop worker training programs in occupational health in Costa Rica. The objectives of this survey were to: 1) describe the safety climate within the national hospital system, 2) identify factors associated with safety, and 3) evaluate the relationship between safety climate and workplace injuries and safety practices of employees. The safety climate was found to be very poor. The two most significant predictors of safety climate were training and administrative support for safety. Safety climate was a statistically significant predictor of workplace injuries and safety practices, respectively, and there was an underreporting rate of 71% of workplace injuries. These findings underscore the need for improvement of the safety climate in the public hospital system in Costa Rica.
Subject(s)
Health Personnel , Hospitals, Public , Occupational Diseases/epidemiology , Occupational Health , Wounds and Injuries/epidemiology , Adult , Costa Rica , Cross-Sectional Studies , Education , Female , Humans , Infant, Newborn , Inservice Training , Male , Occupational Diseases/prevention & control , Occupations , Regression Analysis , Surveys and Questionnaires , Wounds and Injuries/prevention & controlABSTRACT
BACKGROUND: A comprehensive surveillance system for occupational injuries to adolescents does not exist in Texas, as in most states. Therefore, the magnitude, severity, nature, and source of injuries to working adolescents have not been well described in Texas. METHODS: The investigators used three data sources to investigate work-related injuries and deaths in Texas: (1) Texas Workers' Compensation Commission (TWCC) claims data from 1991 through April 1996; (2) 1993 TWCC/Bureau of Labor Statistics (BLS) Annual Survey of Occupational Injuries and Illnesses; and (3) work-related fatalities identified from Texas death certificates from 1990-1995. RESULTS: There were 9,027 injuries reported to the TWCC for adolescents 14-17 years of age during slightly more than 5 years. Injuries for which indemnity payments were made (more than 7 days out of work) occurred among 21.7% of the adolescents. Based on BLS data in 1993, of 992 non-fatal injuries involving days away from work, 35% were caused by contact with objects, 27% by bodily reaction, and 24% by falls. Two-thirds of these injuries occurred while working in eating and drinking places and grocery stores. Three-quarters of the 30 deaths from 1990-1995 were accounted for equally by motor vehicle and homicide. CONCLUSIONS: In conclusion, a substantial number of adolescents are injured or killed in the workplace each year in Texas. Although improved population-based surveillance is needed, sufficient knowledge exists to begin prevention efforts now.
Subject(s)
Accidents, Occupational/statistics & numerical data , Adolescent , Death Certificates , Female , Humans , Male , Texas/epidemiology , WorkplaceABSTRACT
This study assessed the risk of cancer mortality and incidence among 2559 employees exposed to acrylonitrile in the production of Orlon at 2 plants in 1944-1991. Latency, duration of exposure, highest level of exposure ever experienced, and cumulative exposure were used as indicators of exposure. The average duration of exposure for the workers was 7.6 years with an average cumulative exposure of 57.6 ppm-years. Overall mortality was lower than expected in a comparison with the United States population and all DuPont employees [454 deaths, standardized mortality ratios (SMR) of 69 and 91, respectively)]. All the cancer death ratios were lower than expected in a similar comparison. The SMR values for specific sites did not differ significantly from the expected values. Mortality from all cancers and from prostate, respiratory, and digestive cancer did not show any significantly associated increases or a consistent pattern suggestive of a dose-response. The cancer morbidity patterns were similarly unremarkable.
Subject(s)
Acrylic Resins/adverse effects , Acrylonitrile/adverse effects , Cause of Death , Chemical Industry/statistics & numerical data , Neoplasms/chemically induced , Neoplasms/epidemiology , Occupational Exposure/statistics & numerical data , Adult , Aged , Cohort Studies , Confidence Intervals , Environmental Monitoring , Epidemiological Monitoring , Female , Humans , Incidence , Male , Middle Aged , Morbidity , Neoplasms/mortality , Occupational Exposure/adverse effects , Risk Factors , Time Factors , United States/epidemiologyABSTRACT
The long-term health effects of human exposure to polybrominated biphenyls are not known. In this nested case-control study, we evaluated the association between site-specific cancer risk and serum polybrominated biphenyl levels among a Michigan cohort accidentally exposed to polybrominated biphenyls in 1973. The Michigan Department of Public Health has followed 3,899 people through 1993, among whom 195 primary cancers were identified in 187 persons. Controls were 696 randomly selected cancer-free individuals who were frequency matched to cases by sex and age (in 5-year strata). Baseline serum polybrominated biphenyl levels were measured using standard methods. We found an increasing dose-response relation for digestive system cancer risk with higher serum polybrominated biphenyl category [4-20 parts per billion (ppb), 21-50 ppb, and > 50 ppb] after adjustment for age, family cancer history, cigarette smoking, alcohol drinking, and baseline serum polychlorinated biphenyl level. Adjusted odds ratios (ORs) for each category were 8.23 [95% confidence interval (CI) = 1.27-53.3], 12.3 (95% CI = 0.80-191), and 22.9 (95% CI = 1.34-392), respectively. Univariate analysis for polybrominated biphenyl level and lymphoma risk also showed a dose-response relation, with corresponding ORs of 3.24 (95% CI = 0.24-95.9), 20.5 (95% CI = 1.51-608), and 32.6 (95% CI = 3.33-861).
Subject(s)
Carcinogens , Environmental Exposure/adverse effects , Neoplasms/chemically induced , Neoplasms/epidemiology , Polybrominated Biphenyls/adverse effects , Adult , Aged , Case-Control Studies , Cohort Studies , Confidence Intervals , Digestive System Neoplasms/blood , Digestive System Neoplasms/chemically induced , Digestive System Neoplasms/epidemiology , Dose-Response Relationship, Drug , Environmental Exposure/analysis , Environmental Exposure/statistics & numerical data , Female , Humans , Logistic Models , Lymphoma/blood , Lymphoma/chemically induced , Lymphoma/epidemiology , Male , Michigan/epidemiology , Middle Aged , Multivariate Analysis , Neoplasms/blood , Odds Ratio , Polybrominated Biphenyls/blood , Population Surveillance , Registries/statistics & numerical data , Risk FactorsABSTRACT
A method is presented which links on-site electromagnetic field monitoring data with pre-existing work history data. The linkage is used to estimate cumulative and average annualized magnetic field exposure for a case-control study. On-site electromagnetic field monitoring data for 1,966 volunteer utility employees, at 59 sites in the United States and three other countries, were obtained from a large project (the EMDEX project) designed to collect, analyze, and document 60-Hz electric and magnetic field exposures for a diverse population. These data represent 9 primary work environments, and 16 job classification categories, amounting to 144 unique job categories which were consolidated using the job-exposure matrix presented into 282 three-digit Dictionary of Occupational Title (DOT) codes. The DOT code categories were then linked to lifetime occupational histories from a case-control study of leukemia. The method may be extended to link additional job titles with monitoring information. Job titles linked with electromagnetic field monitoring information provide more specific estimates of exposure intensity than previous ordinal estimates of exposure. Therefore, estimates of cumulative electromagnetic field exposure are achievable, as well as high and low level exposure estimates.
Subject(s)
Databases, Factual , Electromagnetic Fields , Environmental Monitoring , Occupational Exposure/analysis , Case-Control Studies , Humans , Job Description , Leukemia/etiology , Risk Factors , Surveys and QuestionnairesABSTRACT
BACKGROUND: Vital statistics data were used to describe the burden of cancer in Texas. METHODS: Average annual age-adjusted mortality data in Texas (1986 to 1990) for 17 cancer types were compared with the US data for whites and blacks and with California data for Hispanics. Trends were examined from 1980 to 1990 for the entire state and from 1976 to 1989 for 24 geographic regions within the state. RESULTS: Mortality excesses were detected for lung and liver cancer, and deficits for colorectal, breast, and prostate cancers. Rates were generally stable from 1980 to 1990 with several exceptions (lung, liver, colon). Six areas of Texas, including four areas along the Gulf Coast, had relatively more excesses of various cancers, without a discernible pattern by cancer type. CONCLUSIONS: Overall, Texas has fared favorably in cancer mortality when compared with the United States. Enhanced evaluation of the frequency of cancer, as well as the conduct of etiologic research, must await the availability of statewide long-term cancer incidence data.