Validity of self-reported duration of work postures obtained by interview

The aim of the study was to validate interview data concerning the duration of four work postures (1) sitting, (2) standing/walking with hands above shoulder level, (3) standing/walking with hands between shoulder and knuckle level, and (4) standing/walking with hands below knuckle level. The self-reported time spent in each posture was tested in relation to observations and technical measurements in 20 subjects during two full working days. The linear relationships between self-reports and observations were strong for the three postures; sitting (r²=0.55), hands above shoulder level (r²=0.58) and hands below knuckle level (r²=0.69). Thus, using this interview technique, self-reports concerning time spent in (1) sitting, (2) standing/walking with hands above shoulder level and, (3) standing/walking with hands below knuckle level may be accurate enough for studying these work postures in epidemiological studies.     

Serious brain injury from traffic-related causes: Priorities for primary prevention

This study evaluated the incidence and outcome of serious brain injury from traffic-related causes in 695 patients admitted to the Department of Neurosurgery at Karolinska Hospital during 1981–1992. A total of 37.3% of patients were car occupants, 28.1% pedestrians, 12.9% bicyclists, 12.2% car-bicycle/car-moped and 9.5% motorcycle riders. The dominating injury was brain contusion (61.6%) verified with computerized tomography. The level of consciousness was evaluated by the Glasgow Coma Scale (GCS) and outcome by the Glasgow Outcome Scale (GOS) at discharge and 6–36 months thereafter. The final outcome was 67.5% good recovery (GOS 4–5), 11.5% severely disabled (GOS 2–3) and 21.0% GOS 1 or brain dead. Patients with GOS < 4 (32.5%) were severely disabled and motivate priorities for injury prevention. Car occupants represent 40.7% of the total, followed by pedestrians at 33.6% and bicyclists at 18.2%. Much remains to be done in the primary prevention of disabling brain injury to car occupants and pedestrians. In order to achieve a more-effective primary prevention, future research should be directed toward biomechanical aspects of brain contusion as a dominating brain injury.     

人群流行病学的空间分布模型仿真研究

在流行病人群分布模型的研究中,人群流行病学在空间上呈现非周期、几何指数、非线性的特征,分布过程复杂度较高,很难运用单一模型控制.传统的模型仅以小周期模型为基础,对大规模疾病分布建模的过程,以多模型组合逼近完成,缺少约束过程,造成复杂度很高,建模效果不好.为了避免上述缺陷,提出基于约束分类优化算法的人群流行病学空间分布模型.根据约束分类优化相关原理,对流行病的空间分布进行分层约束,得到较为合理的人群流行病种群的分布情况,对流行病种群中的所有个体进行编号处理,通过迭代计算得到最优分布区域的计算结果个体.通过临近地区流行病分布比例,得到人群流行病学的空间位置分布情况.实验结果表明,利用改进算法进行人群流行病学空间分布,能够极大的提高分布建模的准确性,降低建模复杂度.     

Epidemiology of foodborne disease outbreaks caused by Vibrio parahaemolyticus,China, 2003–2008

Vibrio parahaemolyticus is a ubiquitous marine bacterium that has become an important public-health concern worldwide. Consumption of food contaminated with V. parahaemolyticus causes acute gastroenteritis in humans. To gain understanding of epidemiological characteristics of V. parahaemolyticus gastroenteritis outbreak in China, we summarized data on 2003–2008 V. parahaemolyticus gastroenteritis outbreaks in 12 provinces reported to China National Foodborne Diseases Surveillance Network. A food item was implicated if V. parahaemolyticus was isolated from food or based on epidemiologic evidence. From 2003 to 2008, 322 gastroenteritis outbreaks due to V. parahaemolyticus were reported, resulting in 9041 illnesses and 3948 hospitalizations. Outbreak size ranged from 2 to 244 cases, with a median of 20 cases. Most of the outbreaks occurred during April and October. A single food commodity was implicated in 187 (58%) outbreaks, of which 58 (31%) involved meat and meat products, and 52 (28%) involved aquatic products. Outbreaks most frequently occurred in restaurants (39%), cafeterias (30%), and private residences (15%). Outbreaks most frequently attributed to cross contamination (50%). To prevent and control V. parahaemolyticus gastroenteritis outbreaks, food workers and consumers should receive training on avoiding cross contamination of ready-to-eat foods with uncooked seafoods, particularly in warm weather months.     

Injuries associated with inline skating in the European region.

OBJECTIVES: To gain greater awareness and understanding of the circumstances leading to injuries associated with inline skating and to provide indices for determining preventive measures. METHODS: Data on injuries during inline skating were collected from seven member states of the European Union (EU) through the European Home and Leisure Accident Surveillance System (EHLASS). RESULTS: The mean incidence rate for injuries while inline skating is 17 per 100,000 inhabitants. In the EU in 1996, about 65,000 people were treated at an Emergency Department for an inline skate injury (excluding traffic injuries). About 60% of the victims are male, while the age group most at risk is 10-14 years old. Most injuries are due to a fall and wrist injuries are most common. CONCLUSIONS: The results of the analysis give indications for possible preventive measures. Although the features of the injuries often differ per country, the countries can learn from each other in preventing these types of injuries. Educational campaigns should be targeted at young teenagers, use of protective equipment (like wrist protectors) and skating techniques. EHLASS has potential for intercountry comparisons, but its value will improve if selecting hospitals and coding agreements will be standardised.     

Shiftwork experience,age and cognitive performance

Changes of alertness and cognitive efficiency has been suggested in people whose circadian rhythms are disrupted, e.g. night or shift-workers. Data from field and laboratory studies have demonstrated short-term cognitive disturbances related to circadian rhythm disruption. By contrast, little is known about the long-term consequences of chronic sleep deprivation, as can be observed with shift-work, on cognitive abilities. The present paper is aimed at evaluating, on a large cross-sectional sample of workers, the long-term influence of shift-work on verbal memory and speed performances. Participants were 3237 workers aged 32, 42, 52, and 62 years of various occupational statuses included in the VISAT (Aging, Health and Work) cohort. Data collected by questionnaires included items on working hours and shift-work and sleep disorders. Cognitive abilities were assessed using neuropsychological tests. Current male shift-workers had lower cognitive performance than never exposed workers. In the same population, memory performance tended to decrease with increasing shift-work duration. Among former shift-workers, the cognitive performance of the participant having stopped shiftwork more than 4 years ago seemed to be increased, suggesting a possible reversibility of effects. In conclusion, this study demonstrated that cognitive functioning tends to be impaired by a long-term exposure to SW. As found by other authors, neuropsychological performance tends to decrease with the increases in the duration of exposure to SW.     

How do the indoor size distributions of airborne submicron and ultrafine particles in the absence of significant indoor sources depend on outdoor distributions?

Although almost all epidemiological studies of smaller airborne particles only consider outdoor concentrations, people in Central Europe actually spend most of their time indoors. Yet indoor pollutants such as organic gases, allergens and dust are known to play a prominent role, often affecting human health more than outdoor ones. The aim of this study was to ascertain how the indoor particle size distributions of submicron and ultrafine particles correlate with the outdoor concentrations in the absence of significant indoor sources. A typical indoor particle size distribution pattern has one or two modes. In the absence of significant indoor activities such as smoking, cooking etc., outdoor particles were found to be a very important source of indoor particles. The study shows that in the absence of significant indoor sources, the number of indoor concentrations of particles in this size range are clearly lower than the outdoor concentrations. This difference is greater, the higher the number of outdoor concentrations. However, the drop in concentration is not uniform, with the decrease in concentration of smaller particles exceeding that of larger ones. By contrast, the findings with larger particle sizes (diameter > 1 microm) exhibit rather linear concentration decreases. The non-uniform drop in the number of concentrations from outdoors to indoors in our measurements considering smaller particles ( >0.01 microm) is accompanied by a shift of the concentration maxima to larger particle diameters.     

Evaluating building-related symptoms using the US EPA BASE study results

In order to develop baseline data about United States office buildings, the United States Environmental Protection Agency conducted the Building Assessment Survey Evaluation (BASE) study, a systematic survey of 100 randomly selected United States office buildings, in the 1990s. This paper analyzes the self-reported work-related symptoms and job and workplace characteristics of 4326 respondents and compares results to the National Institute for Occupational Safety and Health's (NIOSH) study of 80 'complaint' buildings. Four distinct groups of symptoms, representing 'tiredness', 'mucosal irritation', 'neuropsychological', and 'lower respiratory' conditions emerged from factor analysis of work-related symptoms. The symptom grouping is identical for both surveys. Although the prevalence of each symptom is significantly higher in the NIOSH than in the BASE sample, there is overlap of the symptom distributions. In the BASE survey, 45% of the work force reported at least one work-related health symptom; 20% reported at least three symptoms. These findings imply that it is counterproductive to dichotomize buildings into healthy vs. unhealthy; instead the prevalence of health problems related to buildings span a continuum. PRACTICAL IMPLICATIONS: These results indicate that most office buildings have occupants who report building-related symptoms. This paper provides practical guidance for the comparison of building prevalences to the BASE normative data. Work-related symptom distributions and symptom groups can improve investigators' ability to identify IEQ problems.     

(1-->3)-Beta-D-glucans and respiratory health: a review of the scientific evidence

(1-->3)-Beta-D-glucan are non-allergenic structural cell wall components of most fungi that have been suggested to play a causal role in the development of respiratory symptoms associated with indoor fungal exposure. This review describes the currently available epidemiological literature on health effects of (1-->3)-beta-D-glucan, focusing on atopy, airway inflammation and symptoms, asthma, and lung function. In addition to population studies, studies in human volunteers experimentally exposed to (1-->3)-beta-D-glucan are described as well as relevant animal studies. Furthermore, the review discusses exposure assessment methods, the potential for exposure control and it concludes with identifying research needs. The observational and experimental studies reviewed suggested some association between (1-->3)-beta-D-glucan exposure, airway inflammation and symptoms, however, results were mixed and specific symptoms and potential underlying inflammatory mechanisms associated with exposure could not be identified. Large observational studies using well validated exposure assessment methods are needed to further our knowledge regarding the potential health effects of indoor (1-->3)-beta-D-glucan exposure. PRACTICAL IMPLICATIONS: The currently available epidemiological data do not permit conclusions to be drawn regarding the presence (or absence) of an association between environmental (1-->3)-beta-D-glucan exposure and specific adverse health effects, nor is it clear from the currently available evidence which specific immunological mechanisms underlie the presumed health effects. More and larger observational studies are needed to asses whether (1-->3)-beta-D-glucan exposure plays a significant role in respiratory morbidity. In addition, existing methods to assess environmental (1-->3)-beta-D-glucan exposure require validation and further development before they can be used routinely in large scale epidemiological studies.