Risk of acute respiratory infection from crop burning in India: estimating disease burden and economic welfare from satellite and national health survey data for 250 000 persons.

BACKGROUND: Respiratory infections are among the leading causes of death and disability globally. Respirable aerosol particles released by agricultural crop-residue burning (ACRB), practised by farmers in all global regions, are potentially harmful to human health. Our objective was to estimate the health and economic costs of ACRB in northern India. METHODS: The primary outcome was acute respiratory infection (ARI) from India's fourth District Level Health Survey (DLHS-4). DLHS-4 data were merged with Moderate-Resolution Imaging Spectroradiometer satellite data on fire occurrence. Mutually adjusted generalized linear models were used to generate risk ratios for risk factors of ARI. Overall disease burden due to ACRB was estimated in terms of disability-adjusted life years. RESULTS: Seeking medical treatment for ARI in the previous 2 weeks was reported by 5050 (2%) of 252 539 persons. Living in a district with intense ACRB-the top quintile of fires per day-was associated with a 3-fold higher risk of ARI (mutually adjusted risk ratio 2.99, 95% confidence interval 2.77 to 3.23) after adjustment for socio-demographic and household factors. Children under 5 years of age were particularly susceptible (3.65, 3.06 to 4.34 in this subgroup). Additional ARI risk factors included motor-vehicle congestion (1.96, 1.72 to 2.23), open drainage (1.91, 1.73 to 2.11), cooking with biomass (1.73, 1.58 to 1.90) and living in urban areas (1.35, 1.26 to 1.44). Eliminating ACRB would avert 14.9 million disability-adjusted life years lost per year, valued at US$152.9 billion over 5 years. CONCLUSIONS: Investments to stop crop burning and offer farmers alternative crop-residue disposal solutions are likely to improve population-level respiratory health and yield major economic returns.

Considering spatial heterogeneity in the distributed lag non-linear model when analyzing spatiotemporal data.

The distributed lag non-linear (DLNM) model has been frequently used in time series environmental health research. However, its functionality for assessing spatial heterogeneity is still restricted, especially in analyzing spatiotemporal data. This study proposed a solution to take a spatial function into account in the DLNM, and compared the influence with and without considering spatial heterogeneity in a case study. This research applied the DLNM to investigate non-linear lag effect up to 7 days in a case study about the spatiotemporal impact of fine particulate matter (PM2.5) on preschool children's acute respiratory infection in 41 districts of northern Taiwan during 2005 to 2007. We applied two spatiotemporal methods to impute missing air pollutant data, and included the Markov random fields to analyze district boundary data in the DLNM. When analyzing the original data without a spatial function, the overall PM2.5 effect accumulated from all lag-specific effects had a slight variation at smaller PM2.5 measurements, but eventually decreased to relative risk significantly <1 when PM2.5 increased. While analyzing spatiotemporal imputed data without a spatial function, the overall PM2.5 effect did not decrease but increased in monotone as PM2.5 increased over 20 µg/m3. After adding a spatial function in the DLNM, spatiotemporal imputed data conducted similar results compared with the overall effect from the original data. Moreover, the spatial function showed a clear and uneven pattern in Taipei, revealing that preschool children living in 31 districts of Taipei were vulnerable to acute respiratory infection. Our findings suggest the necessity of including a spatial function in the DLNM to make a spatiotemporal analysis available and to conduct more reliable and explainable research. This study also revealed the analytical impact if spatial heterogeneity is ignored.

Assessment of occupational and public exposure to trichloramine in Swiss indoor swimming pools: a proposal for an occupational exposure limit.

OBJECTIVES: The presence of trichloramine in the air in different indoor swimming pools has been studied in several countries. In almost all studies, the results show a possible health impact due to trichloramine among pool attendants. The main objectives of our study were to evaluate, for the first time in Switzerland, occupational and public trichloramine exposure in a representative panel of indoor pools and to propose an occupational exposure limit for trichloramine. METHODS: Measurements were done in 30 indoor swimming pools located in three regions of Switzerland: Jura, Neuchâtel, and Fribourg. All investigations were performed during the 2007-2008 winter season in order to assure closed windows and standard ventilation conditions. Trichloramine air samplings were performed at 130 cm above the floor around the pool. Analyses of free chlorine and bounded chlorine were performed on-site, and water samples were immediately sent to the laboratory for analysis of trihalomethanes, urea, and dissolved organic carbon. A health questionnaire was distributed to all the participants. RESULTS: Our results indicate that in all the studied facilities except one, the trichloramine concentrations were below the French reference value of 0.5 mg m(-3), and only three were equal to or slightly over 0.3 mg m(-3). Overall, our results point out a very low and consistent range of trichloramine concentrations (mean concentration of trichloramine: 0.114 ± 0.043 mg m(-3)). A total of 184 questionnaires were filled out by pool workers. Of the study population, 66% were men (n = 117), 21% were smokers (9 women and 29 men), and only 7% (n = 13) were ex-smokers. The control group was composed of 71 persons (38 men and 33 women); 22% (n = 15) were smokers and 24% (n = 16) ex-smokers. CONCLUSIONS: Our results demonstrate an increasing risk of irritative symptoms up to a level of 0.2-0.3 mg m(-3) of trichloramine. The health data in our study, as well as the review of the literature, strongly suggest fixing the trichloramine occupational exposure limit at 0.3 mg m(-3). Severe technical standards (on flocculation, filters, water flow, and ventilation systems) and regulations on water quality (free and combined chlorine, urea, and amount of fresh water) contribute to reducing trichloramine formation and, consequently, occupational and public trichloramine exposure. In addition, to ensure good public hygiene (showering before swimming), correct and regular public awareness campaigns should be undertaken.

Etanercept in rheumatoid arthritis.

Etanercept (Enbrel, Immunex Corporation, Seattle, Washington, USA) is a new biological disease-modifying antirheumatic drug (DMARD) for the treatment of active rheumatoid arthritis (RA). It is one of two TNF-alpha blockers to be licensed for the treatment of active RA and is classified as a recombinant human soluble TNF receptor. The drug competitively inhibits the binding of TNF to cell surface receptors and thus renders TNF biologically inactive. In doing so, etanercept inhibits the pro-inflammatory effects of TNF and results in a reduction of joint inflammation in patients with RA. Etanercept has shown a statistically significant reduction in swollen and inflamed joint counts, biochemical markers such as erythrocyte sedimentation rate and C-reactive protein and shown significant improvements in quality of life measures (HAQ and global assessment scores) in all studies. In early disease, etanercept has shown a reduction in joint space narrowing equal to methotrexate (MTX) and a reduction in the appearance of new erosions significantly better than MTX after 1 year of treatment. Etanercept has a rapid onset of action which is significantly faster than standard DMARDs. Etanercept was well-tolerated in clinical trials. The commonest side effects were injection site reactions and upper respiratory tract infections. Etanercept therapy has resulted in serious infections in some patients and should be used with caution in any patient with a history of recurring infections or with disease states that may predispose to infections. In summary, etanercept is an effective and well-tolerated agent that is a significant breakthrough in the treatment of this disabling condition.

Risk assessment of the occupational contact with ammonium.

The aim of the cohort retrospective study was to analyze and evaluate the influence of certain factors (age, profession, smoking) on the characteristics and the incidence rate of the upper respiratory tract diseases (URTDs) in the occupational contact with ammonium. Subjects were 180 men, divided into 3 professional groups. The average shift concentrations of ammonium were measured in the permanent work places and individually by personal passive dosemeters. The URTDs were classified into 15 groups according to localization and the stage of the inflammatory process. The relationships "time-response" and "dose (concentration)-response" were determined. The factor "cumulative exposure" was used in order to evaluate the actual noxious effect of NH3 on the mucose of the upper respiratory tract (URT). There was a statistically reliable difference found in the incidence rate of atrophic rhinitis, hypertrophic pharyngitis and laryngitis, and neoplasms of the URT in the workers with the highest cumulative exposure. For this group relative risk was 4.00, 2.22, 3.20 and 4.00, respectively, with 95% Cl. The "cumulative exposure" factor gives the best proofs for the toxic effect of ammonium and a possibility for assessment of the relative risk.