安徽地区儿童暴露于农村生活环境对过敏性哮喘的影响

目的 研究暴露于农村生活环境对预防儿童哮喘及致敏的保护作用.方法 向2986名在校儿童父母发放哮喘标准调查表,采用放射性变应原荧光酶免疫吸附实验(RAST-FEIA)检测儿童血清中特异性IgE(sIgE)含量.结果 与在城镇生活的儿童相比,暴露于农村生活环境儿童的过敏性哮喘与非过敏性哮喘、过敏性哮鸣及特应性哮呜危险度显著性降低(OR=0.45,95%CI:0.13～0.96:OR=0.41,95%CI:0.15～0.95;OR=0.32,95% CI:0.11～0.62;OR=0.44,95% CI:0.13～0.91).1周岁内暴露与农村生活环境的儿童过敏性哮喘及特应性致敏危险度较低(OR=0.23,95% CI:0.04～0.91;OR=0.32,95%CI:0.17～0.78);若暴露持续至6周岁,过敏性哮喘及特应性致敏危险度更低(OR=0.21,95%CI:0.03～0.87;OR=0.31,95%CI:0.15～0.78).结论 暴露于农村环境对预防儿童过敏性哮喘及致敏的发生可能有保护作用,持续的暴露能加强此作用.     

Exposure to diesel exhaust enhances total IgE in non-atopic dockers

OBJECTIVES: Diesel exhaust particles (DEPs) containing polycyclic aromatic hydrocarbons stimulate the formation of IgE in humans following single and acute exposure. The aim of the present study was to ascertain whether long-standing occupational exposure to DEPs carries a risk of enhanced serum IgE, and of rhinitis or asthma. METHODS: In this cross-sectional study, findings in 76 dockers were compared with those in 63 reference subjects. Among the dockers, drivers and laborers were exposed to diesel emission from forklifts or trucks in the ship-holds, where benzopyrene levels averaged 4.9 ng/m(3). Serum IgE levels were measured by the UNICAP method. Atopy, an evident source of high IgE levels, was assessed by the Phadiatop test. The subjects' clinical and occupational histories were collected. Interval variables were analyzed with Student's t- and Levene's F-tests. The odds ratio (OR) with the 95% confidence interval (CI) was obtained by the exact method at univariate and multivariate (logistic regression) analysis. RESULTS: In view of the large difference in serum IgE (P=0.00001) and the prevalence of respiratory diseases ( P=0.009) between atopic and non-atopic subjects, we analyzed their data separately. For non-atopic subjects, the risk of presenting high IgE was significantly higher (OR=11.4; CI=1.44-526; P=0.013) and the risk of respiratory disease was significantly lower (OR=0.09; CI=0.00-0.73; P=0.016) in drivers and laborers as a whole than in the reference subjects. None of the ORs was significant among atopic individuals. CONCLUSIONS: In non-atopic dockers, long-standing exposure to DEPs at concentrations similar to those in heavily polluted cities increased serum IgE levels but not the incidence of rhinitis or asthma.     

Agricultural pesticide use and risk of glioma in Nebraska, United States

Background: To evaluate the risk of the adult glioma associated with farming and agricultural pesticide use, the authors conducted a population based case control study in eastern Nebraska. Methods: Telephone interviews were conducted with men and women diagnosed with gliomas (n = 251) between 1988 and 1993 and controls (n = 498) randomly selected from the same geographical area. Unconditional logistic regression was used to calculate adjusted odds ratios (ORs) for farming and for use of individual and chemical classes of insecticides and herbicides, including pesticides classified as nitrosatable (able to form N-nitroso compounds upon reaction with nitrite). Non-farmers were used as the reference category for all analyses. Results: Among men, ever living or working on a farm and duration of farming were associated with significantly increased risks of glioma (?55 years on a farm OR = 3.9, 95% CI 1.8 to 8.6); however, positive findings were limited to proxy respondents. Among women, there were no positive associations with farming activities among self or proxy respondents. Specific pesticide families and individual pesticides were associated with significantly increased risks among male farmers; however, most of the positive associations were limited to proxy respondents. For two herbicides and three insecticides, use was positively associated with risk among both self and proxy respondents. Based on a small number of exposed cases, ORs were significantly increased for the herbicides metribuzin (OR = 3.4, 95% CI 1.2 to 9.7) and paraquat (OR = 11.1, 95% CI 1.2 to 101), and for the insecticides bufencarb (OR = 18.9, 95% CI 1.9 to 187), chlorpyrifos (OR = 22.6, 95% CI 2.7 to 191), and coumaphos (OR = 5.9, 95% CI 1.1 to 32). Conclusion: The authors found significant associations between some specific agricultural pesticide exposures and the risk of glioma among male farmers but not among female farmers in Nebraska; however, most of the positive associations were limited to proxy respondents. These findings warrant further evaluation in prospective cohort studies where issues of recall bias are not a concern.     

Risk factors for machinery-related injury among Iowa farmers: a case-control study nested in the Agricultural Health Study

Farm machinery is a major cause of injury morbidity and mortality among farmers. This case-control study assessed risk factors for machinery-related injuries among Iowa farmers. A screener questionnaire sent to 6,999 farmers in 1998 identified 205 farmers who had machinery-related injuries requiring medical advice/treatment in the previous year. Possible risk factors for injury were assessed among these farmers compared with 473 farmers with no injury in the previous year. A multiple logistic regression analysis showed significant associations between machinery-related injury and hours per week spent on farmwork (OR = 2.02; 95% CI 1.38-2.94), fewer years of farming experience (OR = 1.79; 95% CI 1.14-2.79), wearing a hearing aid (OR = 4.37; 95% CI 1.55-12.25), and a high CAGE score suggesting problem drinking (OR = 2.49; 95% CI 1.00-6.19). This is the first study to show associations between machinery-related injury and hearing impairment, problem drinking, and fewer years of farming experience. These findings may be useful for future interventions to decrease injuries related to farm machinery.     

Risk of asthma in the general Spanish population attributable to specific immunoresponse. Spanish Group of the European Community Respiratory Health Survey.

BACKGROUND: Individuals with asthma are more atopic than the general population, but few reports have quantified this association, i.e. the proportion of asthma in the community due to specific immunoresponse. We aimed to determine the population attributable risk of asthma in the community due to atopy, and the quantity and quality of specific immunoresponses to common aeroallergens involved. METHODS: We used data from a cross-sectional study in a random sample of the general Spanish population, 20-44 years old, from five areas. In all, 1816 participants were given a symptoms questionnaire, a methacholine challenge and were assessed for atopy. Bronchial responsiveness (BR) was defined as a > or =20% fall in forced expiratory volume in one second (FEV1) after methacholine. Asthma was defined as symptomatic bronchial responsiveness. Atopy was assessed by measuring serum specific IgE or skin tests for sensitivity to Alternaria, birch, cat, Cladosporium, Dermatophagoides pteronyssinus, olive, Parietaria, ragweed or timothy grass. RESULTS: Sensitivity to any of the individual allergens tested significantly increased the risk of being asthmatic, at least twofold compared to non-atopic individuals. The population attributable risk of atopy in explaining asthma is 41.97% (95% CI: 29.2-60.3) when adjusting for area of residence, age, sex, and smoking. In symptomatic individuals, atopy was an independent factor in producing an early measurable PD20 (methacholine dose producing 20% fall in FEV1), especially in those atopic to two or more aeroallergens, and irrespective of the particular aeroallergen. CONCLUSIONS: Specific immunoresponse is strongly associated with asthma, but positivity to single allergens (quality) and the number of positive immunoresponses (quantity) do not change the per se risk of asthma in atopic individuals.     

Pesticides and respiratory symptoms among farmers

OBJECTIVE: Despite the intensive use of pesticides in agriculture there are few studies assessing the risk of respiratory conditions from this exposure. The study aimed at quantifying the prevalence of respiratory symptoms among farmers and evaluating its relationship with occupational use of pesticides and the prevalence of respiratory symptoms. METHODS: A cross-sectional study was conducted among 1,379 farmers from two municipalities of Southern Brazil in 1996. Frequency and type of chemical exposure and pesticide poisoning were recorded for both sexes. All subjects aged 15 years or older with at least 15 weekly hours of agricultural activity were interviewed. An adapted questionnaire developed by the American Thoracic Society was used for the assessment of respiratory symptoms. Multivariate logistic regression analysis was carried out. RESULTS: More than half (55%) of interviewees were male. The prevalence of asthma symptoms was 12% and chronic respiratory disease symptoms was 22%. Higher odds ratios for both asthma (OR=1.51; 95% CI: 1.07-2.14) and chronic respiratory disease (OR=1.34; 95% CI 1.00-1.81) symptoms were found in women. Logistic regression analysis identified associations between many forms of exposure to pesticides and increased respiratory symptoms. Occurrence of pesticide poisoning was associated with higher prevalence of asthma symptoms (OR=1.54; 95% CI: 1.04-2.58) and chronic respiratory disease symptoms (OR=1.57; 95% CI: 1.08-2.28). CONCLUSIONS: In spite of causality limitations, the study results provide evidence that farming exposure to pesticides is associated with higher prevalence of respiratory symptoms, especially when the exposure is above two days per month.     

High risk of hookworm infection among wastewater farmers in Pakistan

The health risks of wastewater use in agriculture were investigated in the city of Faisalabad, Pakistan, by means of a cross-sectional study. The study showed an increased risk of intestinal nematode infection and hookworm infection, in particular, in wastewater farmers (OR = 31.4, 95% CI 4.1-243) and their children (OR = 5.7, 95% CI 2.1-16) when compared with farming households using regular (non-wastewater) irrigation water. Textile labourers living in the same village as the wastewater farmers showed a lower risk of hookworm infection than wastewater farmers but an increased risk compared with farming households using regular irrigation water. Many urban and peri-urban farmers make a living by using untreated wastewater in the production of fresh produce for the urban market. Banning the use of untreated wastewater would deprive these farmers of their livelihood and affect food supply for the urban population. If treatment of wastewater is not a feasible option, the promotion of footwear and improved hygiene, the construction of toilets, in combination with regular anthelminthic treatment, would be suitable alternatives to safeguard the health of wastewater farmers and their children.     

我国城乡流动人口健康教育现状及其影响因素的差异性分析

目的 了解城乡流动人口健康教育现状及其影响因素,为促进中国流动人口健康素养和健康水平提供参考。方法 利用中国2017年全国流动人口动态监测调查数据,共纳入 169 989名流动人口进行分析。t检验和χ2检验用于组间比较。二元 logistic 回归模型用于分析城乡流动人口健康教育现状及其影响因素。结果 2017年全国流动人口中,农村流动人口健康教育接受率为65.6%;城镇流动人口健康教育接受率为69.6%;二元 logistic 回归分析结果显示,文化程度为中等教育（OR = 1.236, P = 0.003, 95%CI:1.065～1.361)、年人均GRP（gross regional product）在100 000元以上(OR = 0.833, P = 0.007, 95%CI:0.730～0.951)、患有高血压(OR = 0.702, P = 0.002, 95%CI:0.562～0.878)或者患有高血压和糖尿病(OR = 0.072, P = 0.043, 95%CI:0.530～0.989)、本地建立健康档案(OR = 4.238, P＜0.001, 95%CI:3.509～5.119)、和完全认同自己为本地人(OR = 1.412,P = 0.046,95%CI:1.006～1.981)的农村流动人口更愿意接受健康教育;已婚(OR = 0.692,P = 0.000,95%CI:0.671～0.804)、老年人（OR = 0.500, P = 0.020, 95%CI:0.278～0.898)、年人均GRP在100 000元(OR = 0.911,P = 0.034,95%CI:0.837～0.992)以上、患有高血压(OR = 0.820, P = 0.021, 95%CI:0.693～0.970)、自评健康(OR = 1.363, P = 0.018, 95%CI:1.041～1.533)、本地建立健康档案(OR = 3.892, P＜0.001, 95%CI:3.424～4.425)的城镇流动人口更愿意接受健康教育。结论 城乡流动人口接受健康教育水平不均,健康教育影响因素具有差异性。将城乡流动人口作为健康教育服务的重点关注对象,加大对于该群体健康教育服务的投入 ,针对城乡流动人口健康教育影响因素的差异性,进行个性化、差异化的健康教育。     

A case-control study of risk factors for asthma in New Zealand children

OBJECTIVE: As in other English-speaking countries, asthma is a major and increasing health problem in New Zealand. This study examined the risk factors for asthma in children aged 7-9. METHODS: Cases and controls were randomly selected from participants in the Wellington arm of the International Study of Asthma and Allergies in Childhood (ISAAC). Cases were children with a previous diagnosis of asthma and current medication use (n=233), and controls were children with no history of wheezing and no diagnosis of asthma (n=241). RESULTS: After controlling for confounders, factors significantly associated with asthma were maternal (OR=3.36, 95% CI 1.88-5.99) and paternal asthma (OR-2.67, 95% CI 1.42-5.02), and male sex (OR=1.81, 95% CI 1.17-2.81). Children from social classes 5 and 6 or with unemployed parents (OR=2.32, 95% CI 1.22-4.44) were significantly more likely to have asthma than children in social classes 1 and 2. There was no significant association between having polio vaccination (OR=2.48, 95% CI 0.83-7.41), hepatitis B vaccination (OR=0.66, 95% CI 0.42-1.04) or measles/mumps/rubella vaccination (OR=1.43, 95% CI 0.85-2.41) and asthma. CONCLUSIONS: This study has confirmed the associations of family history and lower socio-economic status with current asthma in 7-9 year old children. The role of vaccinations requires further research.     

Agricultural pesticide use and adenocarcinomas of the stomach and oesophagus

Aims: To evaluate the risk of the stomach and oesophageal adenocarcinomas associated with farming and agricultural pesticide use. Methods: Population based case-control study in eastern Nebraska. Telephone interviews were conducted with men and women diagnosed with adenocarcinoma of the stomach (n = 170) or oesophagus (n = 137) between 1988 and 1993, and controls (n = 502) randomly selected from the same geographical area. Unconditional logistic regression was used to calculate adjusted odds ratios (ORs) for farming and for use of individual and chemical classes of insecticides and herbicides, including pesticides classified as nitrosatable (able to form N-nitroso compounds on reaction with nitrite). Non-farmers were used as the reference category for all analyses. Results: Ever living or working on a farm, duration of farming, and size of the farm were not associated with stomach or oesophageal adenocarcinomas. There was no association for either cancer with ever-use of insecticides (stomach OR 0.9, 95% CI 0.6 to 1.4; oesophagus OR 0.7, 95% CI 0.4 to 1.1) or herbicides (stomach OR 0.9, 95% CI 0.5 to 1.4; oesophagus OR 0.7, 95% CI 0.4 to 1.2). Likewise, individual pesticides, including individual nitrosatable pesticides, were not significantly associated with risk. Conclusions: No significant associations were found between specific agricultural pesticide exposures and the risk of stomach or oesophageal adenocarcinomas among Nebraska farmers.     

Risk Factors for Machinery-related Injury among Iowa Farmers: A Case-Control Study Nested in the Agricultural Health Study

Abstract

Farm machinery is a major cause of injury morbidity and mortality among farmers. This case-control study assessed risk factors for machinery-related injuries among Iowa farmers. A screener questionnaire sent to 6,999 farmers in 1998 identified 205 farmers who had machinery-related injuries requiring medical advice/treatment in the previous year. Possible risk factors for injury were assessed among these farmers compared with 473 farmers with no injury in the previous year. A multiple logistic regression analysis showed significant associations between machinery-related injury and hours per week spent on farmwork (OR = 2.02; 95% CI 1.38–2.94), fewer years of farming experience (OR = 1.79; 95% CI 1.14–2.79), wearing a hearing aid (OR = 4.37; 95% CI 1.55–12.25), and a high CAGE score suggesting problem drinking (OR = 2.49; 95% CI 1.00–6.19). This is the first study to show associations between machinery-related injury and hearing impairment, problem drinking, and fewer years of farming experience. These findings may be useful for future interventions to decrease injuries related to farm machinery.     

Farm work, dust exposure and respiratory symptoms among farmers

OBJECTIVE: Environmental working conditions in rural areas, notably exposure to organic and mineral dusts, have been associated with increases in respiratory diseases. The objective of this study was to evaluate the prevalence of respiratory symptoms among farmers and the associations of these with occupational risk factors. METHODS: This cross-sectional study was undertaken in 1996 with 1,379 farmers from Southern Brazil. Sociodemographic and farming-production parameters were collected, as were levels of exposure to organic and mineral dusts. Respiratory symptoms were assessed by a modified version of American Thoracic Society-Division of Lung Disease questionnaire. Multiple logistic regression analysis was used in analyses, controlling for confounding factors. RESULTS: The majority (52%) of interviewees worked in activities with intense exposure to dust. Workers on farms with better economic indicators had a lower prevalence of respiratory symptoms. Poultry workers showed more symptoms of chronic respiratory disease (OR=1.60; 95% CI: 1.05-2.42). Farmers exposed to high concentrations of dust had more than 70% higher risk of asthma symptoms (OR=1.71; 95% CI: 1.10-2.67) and chronic respiratory disease symptoms (OR=1.77; 95% CI: 1.25-2.50). CONCLUSIONS: The rural workers studied herein were exposed to high levels of organic and mineral dusts. Those exposed to higher dust concentrations, such as poultry workers, showed an increased risk of work-related respiratory symptoms. The implementation of respiratory protection programs is recommended, emphasizing workers involved with poultry production.     

Mortality and Morbidity among Farmers,Nonfarming Rural Men,and Urban Referents: A Prospective Population-Based Study

Abstract

A cohort of 1,220 farmers, 1,130 nonfarming rural men, and 1,087 urban referents from Sweden were monitored for 12 years. Farmers had lower mortality than urban referents for all causes of death (hazard ratio [HR] = 0.51; 95% confidence interval [CI], 0.37–0.71), cancer (HR = 0.44; 95% CI, 0.24–0.78) and cardiovascular diseases (HR = 0.60; 95% CI, 0.36–0.99). Nonfarming rural men had lower mortality than urban referents for all causes of deaths (HR = 0.81; 95% CI, 0.70–0.94). Farmers and nonfarming rural men had significantly lower morbidity risks of cancer and of psychiatric disorders than urban referents. Farmers had significantly lower risk of endocrine disorders, cardiovascular disorders, and respiratory disorders. In general, morbidity was lower among nonfarming rural men compared with urban referents and was even lower among farmers. Urban referents had, however, significantly less musculoskeletal disorder morbidity. An urban–rural factor and a farming occupational or lifestyle factor results in lower mortality and morbidity rates except concerning musculoskeletal disorders.     

Risk factors for low back injury among farmers in Iowa: A case-control study nested in the agricultural health study

The aim of this study was to assess risk factors for low back injury requiring medical advice or treatment among Iowa farmers. Although farmers are at risk for low back injury, few studies have addressed risk factors for farm work-related low back injury. We screened 6999 participants in the Iowa portion of the Agricultural Health Study to identify 49 male farmers who reported farm work-related low back injury requiring medical advice or treatment in the previous year. We compared them with 465 uninjured male farmer controls. Multivariable modeling identified four risk factors significantly associated with low back injury: age less than 45 years (OR = 3.32; 95% CI 1.75-6.20), doctor-diagnosed asthma (OR = 4.26; 95% CI 1.49-12.10), education beyond high school (OR = 2.12; 95% CI 1.13-3.90), and difficulty hearing normal conversation (even with a hearing aid, in the case of those using one) (OR = 1.98; 95% CI 1.02-3.80). Although hearing difficulty may be a general risk factor for occupational injury, asthma may be a more specific risk factor for low back injury. Future research to assess the risk factors, asthma and difficulty hearing, may be particularly important, since farmers are at increased risk for hearing loss, and farmers come into contact with many inhaled agents that can cause asthma.     

Mode of delivery is associated with asthma and allergy occurrences in children

PURPOSE: A growing body of evidence indicates that perinatal factors modulate immune development and thereby may affect childhood asthma risk. In this study, we examined the associations between birth by cesarean section (C-section) and atopic disease occurrence in childhood. METHODS: Subjects were born in California between 1975 and 1987 and were 8 to 17 years old during their enrollment in the Children's Health Study. Our analysis was restricted to 3464 children born at or after 37 weeks of gestation with a birth weight of 2500 g or greater based on birth certificate data. Information about sociodemographic factors, reported physician-diagnosed asthma, and other atopic diseases was obtained by using a self-administered structured questionnaire. Logistic regression models were fitted to compute odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Children born by C-section were at increased risk for asthma (OR, 1.33; 95% CI, 1.01-1.75), hay fever (OR, 1.57; 95% CI, 1.24-1.99), and allergy (OR, 1.26; 95% CI, 1.03-1.53) compared with those born vaginally. Risk associated with C-section was the same for children regardless of family history of asthma or allergy. CONCLUSION: We conclude that birth by C-section or processes associated with it may increase the risk for atopic disease in childhood.     

Pesticides associated with wheeze among commercial pesticide applicators in the Agricultural Health Study

Pesticides are potential risk factors for respiratory disease among farmers, but farmers are also exposed to other respiratory toxicants. To explore the association of pesticides with wheeze in a population without other farming exposures, the authors analyzed data from 2,255 Iowa commercial pesticide applicators enrolled in the Agricultural Health Study. Controlling for age, smoking status, asthma and atopy history, and body mass index, the authors calculated odds ratios for the relationship between wheeze and 36 individual pesticides participants had used during the year before enrollment (1993-1997). Eight of 16 herbicides were associated with wheeze in single-agent models; however, the risk was almost exclusively associated with the herbicide chlorimuron-ethyl (odds ratio (OR) = 1.62, 95% confidence interval (CI): 1.25, 2.10). Inclusion of chlorimuron-ethyl in models for the other herbicides virtually eliminated the associations. The odds ratios for four organophosphate insecticides (terbufos, fonofos, chlorpyrifos, and phorate) were elevated when these chemicals were modeled individually and remained elevated, though attenuated somewhat, when chlorimuron-ethyl was included. The association for dichlorvos, another organophosphate insecticide, was not attenuated by chlorimuron-ethyl (OR = 2.48, 95% CI: 1.08, 5.66). Dose-response trends were observed for chlorimuron-ethyl, chlorpyrifos, and phorate; the strongest odds ratio was for applying chlorpyrifos on more than 40 days per year (OR = 2.40, 95% CI: 1.24, 4.65). These results add to the emerging literature linking organophosphate insecticides and respiratory health and suggest a role for chlorimuron-ethyl.     

Infections, medication use, and the prevalence of symptoms of asthma, rhinitis, and eczema in childhood

BACKGROUND: The "hygiene hypothesis" postulates that infections during infancy may protect against asthma and atopy. There is also some evidence that antibiotic and/or paracetamol use may increase the risk of asthma. METHODS: The study measured the association between infections, and medication use early in life and the risk of asthma at age 6-7 years. It involved 1584 children who had been notified to public health services with serious infections at age 0-4 years, and 2539 children sampled from the general population. For both groups, postal questionnaires were completed by parents. RESULTS: There was little difference in the prevalence of current wheezing between the childhood infections group (prevalence = 23.5%) and the general population group (prevalence = 24.3%). There was also little difference whether the major site of infection was gastrointestinal (prevalence = 24.1%), invasive (prevalence = 24.6%) or respiratory (prevalence = 21.1%). However, in both groups, there were associations with antibiotic (OR = 1.78, 95% CI 1.49 to 2.14) or paracetamol (OR = 1.38, 95% CI 1.04 to 1.83) use in the first year of life or recent paracetamol use (OR = 2.10, 95% CI 1.78 to 2.49) and current wheezing. There was a weak protective effect of childhood infections in children who had not used antibiotics in the first year of life (OR = 0.78, 95% CI 0.55 to 1.10). CONCLUSIONS: These findings are consistent with other evidence that antibiotic use early in life may increase the risk of asthma. They are also consistent with some preliminary evidence associating paracetamol use with an increased risk of asthma. Any protective effect of notifiable childhood infections was weak.     

Prenatal and postnatal risk factors for mental retardation among children in Bangladesh

This study evaluated the contribution of prenatal, perinatal, neonatal, and postnatal factors to the prevalence of cognitive disabilities among children aged 2-9 years in Bangladesh. A two-phase survey was implemented in 1987-1988 in which 10,299 children were screened for disability. In multivariate analyses, significant independent predictors of serious mental retardation in rural and urban areas included maternal goiter (rural odds ratio (OR) = 5.14, 95% confidence interval (CI): 1.23, 21.57; urban OR = 4.82, 95% CI: 2.73, 8.50) and postnatal brain infections (rural OR = 29.24, 95% CI: 7.17, 119.18; urban OR = 13.65, 95% CI: 4.69, 39.76). In rural areas, consanguinity (OR = 15.13, 95% CI: 3.08, 74.30) and landless agriculture (OR = 6.02, 95% CI: 1.16, 31.19) were also independently associated with the prevalence of serious mental retardation. In both rural and urban areas, independent risk factors for mild cognitive disabilities included maternal illiteracy (OR = 2.48, 95% CI: 0.86, 7.12), landlessness (OR = 4.27, 95% CI: 1.77, 10.29), maternal history of pregnancy loss (OR = 2.61, 95% CI: 0.95, 7.12), and small for gestational age at birth (OR = 3.86, 95% CI: 1.56, 9.55). Interventions likely to have the greatest impact on preventing cognitive disabilities among children in Bangladesh include expansion of existing iodine supplementation, maternal literacy, and poverty alleviation programs as well as prevention of intracranial infections and their consequences. Further population-based studies are needed to confirm and understand the association between consanguinity and serious cognitive disability.     

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.     

Occupational asthma in New Zealanders: a population based study.

OBJECTIVES: To examine the effect of occupation on respiratory symptoms in a randomly selected adult population aged 20-44 years. METHODS: It is based on the phase II sampling of the New Zealand part of the European Community respiratory health survey. 1609 people (63.9% response rate) completed a detailed respiratory questionnaire. Of those responding, 1174 (73%) underwent skin tests and 1126 (70%) attended to undergo methacholine bronchial challenge. Current occupation was recorded and a previous occupation was also recorded if it had led to respiratory problems. 21 occupational groups were used for analysis for the five definitions of asthma wheezing in the previous 12 months; symptoms related to asthma; bronchial hyperresponsiveness (BHR); BHR with wheezing in the previous 12 months; and BHR with symptoms related to asthma. RESULTS: Prevalence odds ratios (ORs) were significantly increased for farmers and farm workers (OR 4.16, 95% confidence interval (95% CI) 1.33 to 13.1 for the combination of wheezing and BHR). Increased risks of prevalence of asthma were also found for laboratory technicians, food processors (other than bakers), chemical workers, and plastic and rubber workers. Workers had also been divided into high and low risk exposure categories according to relevant publications. The prevalence of wheezing was greater in the high risk group (OR 1.57, 95% CI 0.83 to 2.95) than in the low risk group. Atopy was associated with asthma, but the prevalence of atopy did not differ significantly between occupational exposure groups. The attributable risk of wheezing that occurred after the age of 15 years and that was estimated to be due to occupational exposure (based on the defined high risk group) was 1.9%, but this increased to 3.1% when farmers and food processors (other than bakers) were also included in the high risk group. CONCLUSIONS: This population based study has identified certain occupations significantly associated with combinations of asthmatic symptoms and BHR.