First reported foodborne outbreak associated with microsporidia, Sweden, October 2009

Microsporidia are spore-forming intracellular parasites that infrequently cause disease in immunocompetent persons. This study describes the first report of a foodborne microsporidiosis outbreak which affected persons visiting a hotel in Sweden. Enterocytozoon bieneusi was identified in stool samples from 7/11 case-patients, all six sequenced samples were genotype C. To confirm that this was not a chance finding, 19 stool samples submitted by healthy persons from a comparable group who did not visit the hotel on that day were tested; all were negative for microsporidia. A retrospective cohort study identified 135 case-patients (attack rate 30%). The median incubation period was 9 days. Consumption of cheese sandwiches [relative risk (RR) 4·1, 95% confidence interval (CI) 1·4-12·2] and salad (RR 2·1, 95% CI 1·1-4) were associated with illness. Both items contained pre-washed, ready-to-eat cucumber slices. Microsporidia may be an under-reported cause of gastrointestinal outbreaks; we recommend that microsporidia be explored as potential causative agents in food- and waterborne outbreaks, especially when no other organisms are identified.     

An international outbreak of Salmonella enteritidis associated with lasagne; lessons on the need for cross-national co-operation in investigating food-borne outbreaks.

We investigated an outbreak of Salmonella enteritidis involving at least 19 British tourists returning from one hotel in another European country. A retrospective cohort study of 47 hotel guests identified lasagne as the most likely vehicle of transmission (RR 11.5; 95% CI 3.0-44.1; P < 0.0001). However, difficulties in information exchange and lack of formal mechanisms to agree on the aims of the cross-national investigation hampered efficient management of the outbreak. The factors leading to contamination of the food vehicle were not identified and therefore specific action to prevent reoccurrence could not be taken. There is need to develop protocols for cross-national investigations of outbreaks in Europe which should include specifying objectives, roles and responsibilities of investigators and control agencies, with formal reporting of the outcome of the investigation.     

A cohort study of indoor nitrogen dioxide and house dust mite exposure in asthmatic children

OBJECTIVE: The purpose of this study was to investigate dose-response relationships between asthma symptoms and indoor nitrogen dioxide (NO2) and house dust mite allergen (HDM) in children. METHODS: Asthmatic children from 18 primary schools in Adelaide, Australia, kept a daily symptoms diary over 12 weeks. Home and classroom NO2 levels were measured repeatedly in winter 2000. HDM levels were obtained from beds. Lung function tests were performed at the beginning and at the end of the study period. RESULTS: Data on exposure and respiratory outcomes were gathered for 174 children. For school exposure, the estimated relative symptom rate (RR) for a 10-ppb increase in NO2 for difficulty breathing during the day was 1.09 (95% confidence interval [CI] = 1.03-1.15), at night 1.11 (95% CI = 1.05-1.18), and for chest tightness at night 1.12 (95% CI = 1.07-1.17). Significant symptom rate increases were also found for kitchen NO2 exposure. This was supported by a negative dose-response relationship between percentage predicted forced expiratory volume in 1 second and NO2 (-0.39%; 95% CI = -0.76 to -0.02) for kitchen exposure. Significant threshold effects using a 10-microg/g cutoff point for HDM exposure were established in the sensitized children for nighttime wheeze (RR = 3.62, 95% CI = 1.49-8.77), daytime cough (RR = 1.64, 95% CI = 1.14-2.36), and daytime asthma attack (RR = 1.95, 95% CI = 1.06-3.60). CONCLUSION: This study has established reliable risk estimates for exacerbations of asthma symptoms in children based on dose-response investigations of indoor NO2 and HDM.     

A cross-sectional survey of respiratory and general health outcomes among semiconductor industry workers

As part of the Semiconductor Health Study, we performed a cross-sectional survey to assess prevalence of specific nonreproductive health outcomes and their association with occupational exposures. A total of 3,175 persons from eight manufacturing sites across the U.S. completed a health and work questionnaire (78% participation rate). After adjusting for confounders, responses from fabrication room (fab) workers indicated a greater risk than those of nonfab workers for upper respiratory symptoms (relative risk [RR] = 1.08; 95% confidence interval [CI] = 1.03-1.13); a dose-response effect with hours per day spent in fabs was observed. Fab workers also had greater prevalence for persistent wheezing (RR = 1.82; 95% CI = 1.15-2.87), Dermatitis within the past year (RR = 1.19; 95% CI = 1.04-1.35), and alopecia (RR = 1.73; 95% CI = 1.16-2.54). Female sex, a somatization index score, and smoking were important nonoccupational covariates. Increased respiratory symptoms MAy result from occupational exposures in fabs; further research is needed to identify causal agents and develop prevention strategies.     

An outbreak of cryptosporidiosis associated with a resort swimming pool.

An outbreak of cyptosporidiosis occurred in late April 1993 among resort hotel guests which was temporally associated with, but geographically distant from, a massive waterborne outbreak of cryptosporidiosis in Milwaukee, Wisconsin, that occurred in late March and early April of 1993. A case-control study was performed among groups with members who reported illness and among a systemic sample of groups who stayed at the resort hotel during the risk period. Of 120 persons interviewed, 51 (43%) met the case definition. Swimming in the resort hotel''s pool was significantly associated with case status (OR = 9.8; 95% Cl 3.4, 29.7), as was consumption of ice from the hotel''s ice machines (OR = 2.3; 95% Cl 1.01, 5.2). When analysis was restricted only to laboratory-confirmed cases and controls, swimming pool use was the only risk factor significantly associated with illness (OR = 13.0; 95% Cl 2.6, 88.7). Following waterborne outbreaks of cryptosporidiosis associated with water supplies, swimming pools should be considered as possible ongoing sources for transmission regionally.     

An outbreak of Salmonella typhimurium RDNC A045 at a wedding feast in South Australia

In April 1998 an outbreak of salmonellosis amongst guests at a wedding feast was investigated. Of the 58 attendees interviewed 38 (66%) subsequently developed gastrointestinal symptoms. Stool cultures from 7 cases grew Salmonella Typhimurium RDNC A045. Food samples were culture-negative for Salmonella spp. A cohort study implicated spatchcock (RR 2.5, 95% CI 1.09-5.77) and scampi (RR 2.0, 95% CI 1.05-3.89). Temperature abuse and cross-contamination within the kitchen during preparation and cooking are likely to have been the main contributing factors to this outbreak. Control measures included staff education in safe food handling and improvements in poultry processing methods to minimise carcass contamination.     

Health effects associated with indoor swimming pools: a suspected toxic chloramine exposure

OBJECTIVES: A cohort and environmental study tested the hypothesis that suspected exposure to chloramines (by-products of chlorine for disinfection and ammonia from human sources) from a hotel's indoor swimming pool was associated with an outbreak among children who had attended a party at the pool. STUDY DESIGN: Retrospective cohort study. METHODS: A case was defined as any hotel guest/visitor on 5-6 October 2002 who experienced three or more symptoms typical of chloramine exposure on either day after visiting the hotel. A cohort study and an environmental assessment were performed to determine the association between pool exposure and illness. RESULTS: Of 128 individuals interviewed, 32 met the case definition. Common symptoms among case patients were cough (84%), eye irritation (78%) and rash (34%). Illness was associated with entering the pool area [odds ratio (OR) 19.9; 95% confidence interval (CI) 2.3-172], but more strongly with swimming (OR 72.0; 95% CI 9.1-568). Pool chloramine levels on 6 October 2002 were > or = 0.7ppm (optimal level=0ppm; state maximum=0.5ppm). The pool operator lacked formal training in pool maintenance. CONCLUSIONS: High chloramine levels may have caused illness in individuals who were either in or near the pool. This outbreak underscores the need for regular pool maintenance, improved air quality, education and certification for all operators of public and semipublic pools, and education about healthy swimming practices.     

Tiefkühlfrüchte als Risikofaktor für Gastroenteritis-Ausbrüche durch Noroviren

An outbreak of acute gastroenteritis occurred in Hamburg among guests of a canteen in August 2005. A total of 241 persons were found ill. In stool samples of 16 of them Norovirus Genogroup I was identified. Neither bacterial nor viral pathogens could be detected in food samples. Among 162 guests enrolled in a cohort study, 69 (42.6 %) met the case definition. A desert dish made from blackberries and yoghurt showed a significant association with the disease (RR 6.9; 95% CI 3.36-14.16). In addition, a protective effect of the decision for the alternative desert dish ice cream was observed (RR 0.9; 95% CI 0.08-0.45). The desert, which was prepared in the canteen kitchen from yoghurt and frozen blackberries, was the most likely source of the outbreak. Frozen berries should be included in the HACCP concepts for canteen kitchens.     

An outbreak of Cryptosporidium hominis infection at an Illinois recreational waterpark

Cryptosporidium has become increasingly recognized as a pathogen responsible for outbreaks of diarrhoeal illness in both immunocompetent and immunocompromised persons. In August 2001, an Illinois hospital reported a cryptosporidiosis cluster potentially linked to a local waterpark. There were 358 case-patients identified. We conducted community-based and waterpark-based case-control studies to examine potential sources of the outbreak. We collected stool specimens from ill persons and pool water samples for microscopy and molecular analysis. Laboratory-confirmed case-patients (n=77) were more likely to have attended the waterpark [odds ratio (OR) 16.0, 95% confidence interval (CI) 3.8-66.8], had pool water in the mouth (OR 6.0, 95% CI 1.3-26.8), and swallowed pool water (OR 4.5, 95% CI 1.5-13.3) than age-matched controls. Cryptosporidium was found in stool specimens and pool water samples. The chlorine resistance of oocysts, frequent swimming exposures, high bather densities, heavy usage by diaper-aged children, and increased recognition and reporting of outbreaks are likely to have contributed to the increasing trend in number of swimming pool-associated outbreaks of cryptosporidiosis. Recommendations for disease prevention include alteration of pool design to separate toddler pool filtration systems from other pools. Implementation of education programmes could reduce the risk of faecal contamination and disease transmission.     

Shigellosis outbreaks at summer camps for the mentally retarded in New York State

During 1987, four New York State summer camps for the mentally retarded and developmentally disabled experienced outbreaks of Shigella sonnei gastroenteritis. Cases occurred in 150 of 286 (attack rate (AR) = 52%), 167 of 295 (AR = 57%), and 25 of 114 (AR = 22%) persons in three camps, respectively; a fourth camp reported eight cases. Epidemiologic investigation suggested point-source foodborne outbreaks in two camps, while person-to-person spread appeared to predominate in the other two. Numerous secondary cases were identified among contacts outside the facilities in the second and third camps. To quantify the extent of the problem, the authors reviewed data on 77 infectious disease outbreaks (12 in camps for the handicapped and 65 in camps for the nonhandicapped) that occurred in the 12,484 registered camp sessions (316 for the handicapped and 12,168 for the nonhandicapped) held during the six-year period 1982-1987. Camps for the handicapped demonstrated approximately a seven times greater risk for all types of infectious disease outbreaks (AR = 38 outbreaks/1,000 camp sessions vs. five outbreaks/1,000 camp sessions; relative risk (RR) = 7.1, 95% confidence interval (CI) 3.9-13.0), including those of gastrointestinal etiology (RR = 8.6, 95% CI 4.4-16.8) and those due to Shigella (RR = infinity). Large camp size (RR = 2.3, 95% CI 1.3-4.1) and long duration of camp sessions (RR = 3.9, 95% CI 1.3-11.6) also increased the risk for outbreaks; however, this risk was predominantly in the camps for the nonhandicapped--other factors relating to personal hygiene and close camper-staff contact were probably more important in the camps for the handicapped. These outbreaks demonstrate the impact of shigellosis at summer camps for the mentally retarded and the need for early preventive action.     

Indoor environment and respiratory symptoms in children living in the Dutch-German borderland

OBJECTIVE: To investigate the relation between indoor environmental risk factors and respiratory symptoms in 7-8-year-old children living in the Dutch-German borderland. METHODS: A nested case-control study was conducted among children participating in a large longitudinal study on respiratory health. Parents of all 781 children with respiratory complaints and an equal number of randomly selected controls were asked to complete a questionnaire, including questions on indoor environment. RESULTS: The parents of 1191 children (76.2%) participated. Past exposure to environmental (OR = 2.73, 95% CI 1.14-6.67) as well as in utero exposure (OR = 2.28, 95% CI 1.15-4.53) to tobacco smoke, use of an unvented geyser for water heating (OR = 3.01, 95% CI 1.21-7.56), long-term exposure to dampness (OR = 2.98, 95% CI 1.10-8.28) or pets (OR = 2.18, 95% CI 1.39-3.42) increased the risk of asthmatic symptoms in 7-8-year-old children. A middle or low socio-economic status also increased the risk of asthmatic symptoms. An inverse association with asthmatic symptoms was seen for wall-to-wall carpeting (OR = 0.57, 95% CI 0.33-0.95) and insulation measures (OR = 0.46, 95% CI 0.25-0.83). Except for the presence of an unvented geyser, these environmental risk factors also presented a risk for coughing symptoms in children. CONCLUSION: This study showed an increased risk of respiratory symptoms in children exposed to several indoor environmental risk factors.     

A whirlpool associated outbreak of Pontiac fever at a hotel in Northern Sweden

In April 1999, an outbreak of Pontiac fever occurred at a hotel in Northern Sweden. A retrospective cohort study to find the source and define the extent of the outbreak was carried out among 530 Swedish and Norwegian guests. Twenty-nine epidemiological cases (8% of 378 responders) aged 21-57 years were identified. Antibodies against Legionella micdadei were detected in 17 of 27 tested cases and 3 other symptomatic persons. Visiting the whirlpool area was identified as the sole risk factor (RR 86; 95% CI 21-352) and infected cases were confined to visitors to this area over three successive days. The attack rate was 71% (27/38) and 24 cases (83%) used the whirlpool. Environmental sampling was negative for Legionella sp. But epidemiological investigation strongly suggests that the whirlpool was the source of the outbreak. The possibility of serious legionella infections underlines the importance of strict maintenance practices to maintain hygiene of whirlpools.     

Hospitalization with respiratory disease following hiatal hernia and reflux esophagitis in a prospective, population-based study

PURPOSE: Hiatal hernia and reflux esophagitis have been associated with respiratory manifestations, though the temporal sequence of this relationship is uncertain. This study examined prospectively the relationship of hiatal hernia and reflux esophagitis with respiratory outcomes in a representative sample of the United States population. METHODS: 6928 participants in the first National Health and Nutrition Examination Survey, a population-based sample initially examined in 1971-1975, who were hospitalized during follow-up through 1992-1993 composed the study population. The relationship between hiatal hernia and reflux esophagitis hospitalization and a subsequent hospitalization with respiratory outcomes was measured in persons free of respiratory disease at baseline and at first hospitalization. RESULTS: Multivariable survival analysis showed higher rates of hospitalization with any respiratory diagnosis [rate ratio (RR) = 1.4, 95% confidence interval (CI) 1.2-1.7] in persons with preceding hiatal hernia or reflux esophagitis hospitalization. Individually, rate ratios of pharyngitis (RR = 5.6, CI 2.0-15.7), tonsillitis (RR = 8.0, CI 2.5-25.8), bronchitis (RR = 1.8, CI 1.2-2.7), pneumonia (RR = 1.3, CI 1.0-1.7), emphysema (RR = 2.9, CI 1.5-5.5), asthma (RR = 2.1, CI 1.1-4.2), bronchiectasis (RR = 6.2, CI 1.1-34.3), and empyema or abscess (RR = 7.4, CI 1.3-42.3) were all higher following hiatal hernia and reflux esophagitis. Rate ratios were similar when reflux esophagitis and hiatal hernia were examined separately. CONCLUSIONS: A prior hiatal hernia or reflux esophagitis hospitalization increased risk of respiratory disease hospitalization.     

Prenatal Ambient Air Exposure to Polycyclic Aromatic Hydrocarbons and the Occurrence of Respiratory Symptoms over the First Year of Life

The purpose of the study was to test the hypothesis that infants with higher levels of prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) from fossil fuel combustion may be at greater risk of developing respiratory symptoms. The study was carried out in a cohort of 333 newborns in Krakow, Poland, followed over the first year of life, for whom data from prenatal personal air monitoring of mothers in the second trimester of pregnancy were available. The relative risks of respiratory symptoms due to prenatal PAHs exposure were adjusted for potential confounders (gender of child, birth weight, maternal atopy, maternal education as a proxy for the socio-economic status, exposure to postnatal environmental tobacco smoke, and moulds in households) in the Poisson regression models. Increased risk related to prenatal PAH exposure was observed for various respiratory symptoms such as barking cough (RR = 4.80; 95% CI: 2.73–8.44), wheezing without cold (RR = 3.83; 95% CI: 1.18–12.43), sore throat (RR = 1.96; 95% CI: 1.38–2.78), ear infection (RR = 1.82; 95% CI: 1.03–3.23), cough irrespective of respiratory infections (RR=1.27; 95% CI: 1.07–1.52), and cough without cold (RR = 1.72; 95% CI: 1.02–2.92). The exposure to PAHs also had impact on the duration of respiratory symptoms. The effect of PAHs exposure on the occurrence of such symptoms as runny nose or cough was partly modified by the simultaneous exposure to postnatal passive smoking. The analysis performed for the duration of respiratory symptoms confirmed significant interaction between PAHs exposure and postnatal ETS for runny or stuffy nose (RR = 1.82; 95% CI: 1.57–2.10), cough (RR = 1.18; 95% CI: 0.99–1.40), difficulty in breathing (RR = 1.39; 95% CI: 1.01–1.92) and sore throat (RR = 1.74; 1.26–2.39). Obtained results support the hypothesis that prenatal exposure to immunotoxic PAHs may impair the immune function of the fetus and subsequently may be responsible for an increased susceptibility of newborns and young infants to respiratory infections.     

Indoor allergens, asthma, and asthma-related symptoms among adolescents in Wuhan, China

PURPOSE: Information on indoor allergen exposures among non-Western populations, which have lower prevalence of atopic illness, is scant. We examined whether exposures to common indoor allergens were associated with doctor-diagnosed asthma and asthma-related symptoms among Chinese adolescents. METHODS: A cross-sectional study of 4,185 ninth grade students was conducted at 22 randomly selected schools in Wuhan, China. Information on respiratory health and exposures to indoor allergens was obtained by a self-administered questionnaire completed in class. RESULTS: Having animals currently was associated with persistent cough [prevalence odds ratio (POR)=1.54, 95% confidence interval (CI ): 1.21-2.11] and wheeze (POR=1.41, 95% CI: 1.03-1.94). Early-life exposure to animals was also associated with doctor-diagnosed asthma (POR=1.95, 95% CI: 1.35-2.82). Associations with respiratory symptoms strengthened with higher levels of exposure and for exposure in both early childhood and in adolescence. Exposure to cockroaches and having mold/water damage in the home contributed especially to wheezing (POR=2.03, 95% CI: 1.41-2.90 for cockroaches; POR=2.49, 95% CI: 1.82-3.40 for mold/water damage). CONCLUSIONS: Indoor allergen exposures were positively associated with asthma diagnosis and persistent respiratory symptoms among Chinese adolescents. Neither early-life nor current exposure to animals was protective for asthma or asthma-related symptoms.     

Cardiovascular and respiratory hospitalizations and mortality among users of tiotropium in Denmark

Tiotropium (Spiriva is an inhaled, once-daily anticholinergic medication for chronic obstructive pulmonary disease (COPD). We conducted a population-based cohort study to examine the risk of cardiovascular and respiratory hospitalizations and mortality with tiotropium. Using the Danish healthcare registries, we identified persons >/=40 years old in three counties who were hospitalized for COPD from 1/1/1977 to 12/31/2003. Respiratory and cardiovascular medications were assessed from dispensing records. Cox regression was used to compute incidence rate ratios (RR) and 95% confidence intervals (CI) for hospitalization and death between 1/1/2002 and 12/31/2003, associated with periods of tiotropium use compared to non-use, controlling for age, gender, time since COPD, concomitant respiratory and cardiovascular medications, prior hospitalizations and Charlson comorbidity index. Among persons with COPD (10,603), 75% were >/=60 years old. Follow-up was >/=18 months for 64%. Among those exposed to tiotropium compared to periods of non-use, the RR for total and cause-specific hospitalization endpoints were not elevated except for COPD hospitalization (RR = 1.52, 95% CI: 1.29, 1.79). Mortality endpoints included total mortality (RR = 0.77, 95% CI: 0.65, 0.91), respiratory mortality (RR = 0.79, 95% CI: 0.60, 1.04), sudden death (RR = 0.71, 95% CI: 0.21, 2.34), cardiac arrest (RR = 0.74, 95% CI: 0.42, 1.32), heart failure (RR = 0.84, 95% CI: 0.41, 1.75), and myocardial infarction (RR = 1.25, 95% CI: 0.49, 3.17). Compared to periods of non-use, tiotropium was associated with reduced respiratory and overall mortality and was not associated with increased cardiac mortality. An increase in COPD hospitalization is inconsistent with clinical trial data and suggests preferential prescribing due to disease severity.     

Indoor exposures and acute respiratory effects in two general population samples from a rural and an urban area in Italy

A study of indoor air exposures and acute respiratory effects in adults was conducted in the Po Delta (rural) and Pisa (urban) areas of Italy. Indoor exposures were monitored for nitrogen dioxide (NO(2)) and particulate matter <2.5 microm (PM(2.5)) for 1 week during the winter or summer in a total of 421 houses (2/3 in Pisa). Information on house characteristics, subjects' daily activity pattern and presence of acute respiratory symptoms was collected by a standardized questionnaire. Peak expiratory flow (PEF) maneuvers were performed by adult subjects four times daily; maximum amplitude and diurnal variation were taken into account. Indices of NO(2) and PM(2.5) exposures were computed as the product of weekly mean pollutant concentration by the time of daily exposure. Mean levels of pollutants were significantly higher in winter than in summer, regardless of the area. The relationship between exposure indices and acute respiratory symptoms was investigated only in winter. In spite of a slightly lower indoor level in the urban than in the rural area in winter (NO(2): 15 vs. 22 ppb; PM(2.5): 67 vs. 76 microg/m(3)), prevalence rates of acute respiratory symptoms were significantly higher in the urban than in the rural area. Acute respiratory illnesses with fever were significantly associated with indices of NO(2) (odds ratio (OR)=1.66; 95% CI=1.08-2.57) and PM(2.5) exposures (OR=1.62; 95% CI=1.04-2.51), while bronchitic/asthmatic symptoms were associated only with PM(2.5) (OR=1.39; 95% CI=1.17-1.66). PEF variability was positively related only to PM(2.5) exposure index (OR=1.38; 95% CI=1.24-1.54, for maximum amplitude; OR=1.37; 95% CI=1.23-1.53, for diurnal variation). In conclusion, indoor pollution exposures were associated with the presence of acute respiratory symptoms and mild lung function impairment in a rural and an urban area of Northern-Central Italy.     

Waterborne outbreak of gastroenteritis transmitted through the public water supply

INTRODUCTION: The chlorination of public water supplies has led researchers to largely discard drinking water as a potential source of gastroenteritis outbreaks. The aim of this study was to investigate an outbreak of waterborne disease associated with drinking water from public supplies. METHODS: A historical cohort study was carried out following notification of a gastroenteritis outbreak in Baqueira (Valle de Arán, Spain). We used systematic sampling to select 87 individuals staying at hotels and 67 staying in apartments in the target area.Information was gathered on four factors (consumption of water from the public water supply, sandwiches, water and food in the ski resorts) as well as on symptoms. We assessed residual chlorine in drinking water, analyzed samples of drinking water, and studied stool cultures from 4 patients. The risk associated with each water source and food type was assessed by means of relative risk (RR) and 95% confidence intervals (CI). RESULTS: The overall attack rate was 51.0% (76/149). The main symptoms were diarrhea 87.5%, abdominal pain 80.0%, nausea 50.7%, vomiting 30.3%, and fever 27.0%. The only factor associated with a statistically significant risk of disease was consumption of drinking water (RR = 11.0; 95% CI, 1.6-74.7). No residual chlorine was detected in the drinking water, which was judged acceptable. A problem associated with the location of the chlorinator was observed and corrected. We also recommended an increase in chlorine levels, which was followed by a reduction in the number of cases. The results of stool cultures of the four patients were negative for enterobacteria. CONCLUSIONS: This study highlights the potential importance of waterborne outbreaks of gastroenteritis transmitted through drinking water considered acceptable and suggests the need to improve microbiological research into these outbreaks (viruses and protozoa detection).     

2018-2019年六安市宾馆室内空气卫生状况及影响因素分析

目的了解六安市部分宾馆室内空气卫生现状,分析室内工作场所环境对呼吸系统的影响,为加强公共场所卫生管理提供科学依据。方法于2018-2019年对六安市部分公共场所进行卫生监测和评价,并通过从业人员健康危因素问卷分析呼吸系统感觉或症状与工作场所环境的关系。使用Excel 2010软件整理数据,利用SPSS 21.0分析数据,率的比较采用卡方检验,检验水准α=0.05。结果2018-2019年共检测163个酒店房间,检测项目合计1467项次。在各项检测指标中合格率前两位分别是CO2体积分数和甲醛,湿度和PM2.5合格率较低,分别为34.97%和38.04%。2019年相比2018年温度合格率上升,湿度和PM10合格率下降,差异有统计学意义(P<0.05)。不同轮次的温度、湿度、甲醛、PM2.5、细菌总数、PM10、CO2差异有统计学意义(P<0.05)。不同星级的宾馆温度、PM10差异有统计学意义(P<0.05)。细菌总数与湿度呈正相关,真菌总数与温度呈负相关。PM2.5、PM10质量浓度与温度及湿度呈负相关。甲醛与温度呈正相关。室内PM10、PM2.5与室外PM10、PM2.5呈正相关。宾馆冷却塔嗜肺军团菌2018年合格率为100%,2019年合格率为25%。宾馆从业人员呼吸系统感觉或症状的环境危害因素为空气干燥(OR=2.424,95%CI:1.257~4.677)、有刺激性气味(OR=4.708,95%CI:1.673~13.251)、有霉味(OR=2.210,95%CI:1.002~4.876)和空气中有灰尘(OR=1.926,95%CI:1.035~3.586)。结论夏季甲醛浓度因受温度和湿度影响其合格率比冬季低。冬季室内颗粒物浓度因受室外空气质量影响,比夏季高。三星级及以上宾馆温度的合格率较高,快捷宾馆PM10合格率较高。在室外空气质量好的情况下,应加强开窗通风或机械通风,并应完善室内空气和空调系统消毒制度,从而改善室内微小气侯,并应加强室内空气有害物质监测和治理。     

Effect of outdoor and indoor nitrogen dioxide on respiratory symptoms in schoolchildren

BACKGROUND: Nitrogen dioxide (NO(2)), an oxidant gas that contaminates both outdoor and indoor air, is considered to be a potential risk factor for asthma. We investigated concurrently the effects of outdoor and indoor NO(2) on the prevalence and incidence of respiratory symptoms among children. METHODS: A cohort study was carried out over 3 years on 842 schoolchildren living in seven different communities in Japan. Indoor NO(2) concentrations over 24 hours were measured in both winter and summer in the homes of the subjects, and a 3-year average of the outdoor NO(2) concentration was determined for each community. Respiratory symptoms were evaluated every year from responses to questionnaires. RESULTS: The prevalence of bronchitis, wheeze, and asthma significantly increased with increases of indoor NO(2) concentrations among girls, but not among boys. In neither boys nor girls were there significant differences in the prevalence of respiratory symptoms among urban, suburban, and rural districts. The incidence of asthma increased among children living in areas with high concentrations of outdoor NO(2). Multiple logistic regression analysis showed that a 10 parts per billion (ppb) increase of outdoor NO(2) concentration was associated with an increased incidence of wheeze and asthma (odds ratios [OR] = 1.76, 95% CI : 1.04-3.23 and OR = 2.10, 95% CI : 1.10-4.75, respectively), but that no such associations were found with indoor NO(2) concentration (OR = 0.73, 95% CI : 0.45-1.14 and OR = 0.87, 95% CI : 0.51-1.43, respectively). CONCLUSIONS: These findings suggest that outdoor NO(2) air pollution may be particularly important for the development of wheeze and asthma among children. Indoor NO(2) concentrations were associated with the prevalence of respiratory symptoms only among girls. Girls may be more susceptible to indoor air pollution than boys.