Sukon Kanchanaraksa

Home environmental intervention in inner-city asthma: a randomized controlled clinical trial

BACKGROUND Airborne pollutants and indoor allergens increase asthma morbidity in inner-city children; therefore, reducing exposure, if feasible, should improve asthma morbidity. OBJECTIVE To conduct a randomized controlled trial of methods to reduce environmental pollutant and allergen exposure in the homes of asthmatic children living in the inner city. METHODS After the completion of questionnaires, spirometry and allergen skin tests, home inspection, and measurement of home air pollutant and allergen levels, 100 asthmatic children aged 6 to 12 years were randomized to the treatment group (home-based education, cockroach and rodent extermination, mattress and pillow encasings, and high-efficiency particulate air cleaner) or to the control group (treated at the end of the 1-year trial). Outcomes were evaluated by home evaluations at 6 and 12 months, clinic evaluation at 12 months, and multiple telephone interviews. RESULTS In the treatment group, 84% received cockroach extermination and 75% used the air cleaner. Levels of particulate matter 10 microm or smaller declined by up to 39% in the treatment group but increased in the control group (P < .001). Cockroach allergen levels decreased by 51% in the treatment group. Daytime symptoms increased in the control group and decreased in the treatment group (P = .04). Other measures of morbidity, such as spirometry findings, nighttime symptoms, and emergency department use, were not significantly changed. CONCLUSIONS A tailored, multifaceted environmental treatment reduced airborne particulate matter and indoor allergen levels in inner-city homes, which, in turn, had a modest effect on morbidity.

Cockroach allergen abatement with extermination and sodium hypochlorite cleaning in inner-city homes

BACKGROUND Although the importance of cockroach allergen in chronic asthma has now been well defined, little progress has been made in the control of cockroach allergen in infested homes. OBJECTIVE The objective of this study was to examine the ability of a combination of professional pest extermination and household cleaning using a solution of sodium hypochlorite to reduce cockroach infestation and allergen levels in cockroach infested homes. METHODS Seventeen cockroach-infested homes were studied with three homes serving as controls. In the intervention homes, a professional exterminator applied 0.05% abamectin twice at 2-week intervals at study entry and a professional cleaner cleaned the homes before and after the extermination. All washable surfaces were cleaned throughout the study with a solution of 0.5% hypochlorite. Monthly home visits were conducted to inspect the home, interview the homeowner, place passive cockroach traps, and to collect settled dust samples from the kitchen, bedroom, and TV/living room. RESULTS The number of cockroaches in the passive traps decreased rapidly after the initial intervention in most homes. Median Blatella germanica allergen 1 levels in the settled dust samples fell by 91% in the kitchen, 78% in the bedroom, and 77% in the living room over the course of the study in the intervention homes but gradually rose in the control homes. The overall reductions were very similar to those seen in a previous study with a similar protocol except for the use of the sodium hypochlorite. CONCLUSIONS Successful extermination is possible in most inner-city homes and cockroach allergen levels can be reduced by 80% to 90%. However, 0.5% sodium hypochlorite did not seem to improve allergen reduction, and in many homes, allergen levels remained above the proposed threshold of 8 U/g of dust throughout the study.

A comparison of online versus on-site training in health research methodology: a randomized study.

AbstractBackgroundDistance learning may be useful for building health research capacity. However, evidence that it can improve knowledge and skills in health research, particularly in resource-poor settings, is limited. We compared the impact and acceptability of teaching two distinct content areas, Biostatistics and Research Ethics, through either on-line distance learning format or traditional on-site training, in a randomized study in India. Our objective was to determine whether on-line courses in Biostatistics and Research Ethics could achieve similar improvements in knowledge, as traditional on-site, classroom-based courses.MethodsSubjects: Volunteer Indian scientists were randomly assigned to one of two arms. Intervention: Students in Arm 1 attended a 3.5-day on-site course in Biostatistics and completed a 3.5-week on-line course in Research Ethics. Students in Arm 2 attended a 3.5-week on-line course in Biostatistics and 3.5-day on-site course in Research Ethics. For the two course formats, learning objectives, course contents and knowledge tests were identical. Main Outcome Measures: Improvement in knowledge immediately and 3-months after course completion, compared to baseline.ResultsBaseline characteristics were similar in both arms (n = 29 each). Median knowledge score for Biostatistics increased from a baseline of 49% to 64% (p < 0.001) 3 months after the on-site course, and from 48% to 63% (p = 0.009) after the on-line course. For the on-site Research Ethics course, median score increased from 69% to 83% (p = 0.005), and for the on-line Research Ethics course from 62% to 80% (p < 0.001). Three months after the course, median gains in knowledge scores remained similar for the on-site and on-line platforms for both Biostatistics (16% vs. 12%; p = 0.59) and Research Ethics (17% vs. 13%; p = 0.14).ConclusionOn-line and on-site training formats led to marked and similar improvements of knowledge in Biostatistics and Research Ethics. This, combined with logistical and cost advantages of on-line training, may make on-line courses particularly useful for expanding health research capacity in resource-limited settings.

Industry-Wide Study of Mortality of Pulp and Paper Mill Workers

A study of pulp and paper mill workers indicated low risks of death from all causes (standardized mortality ratio (SMR) = 0.74) and all cancers (SMR = 0.81) compared with U.S. rates. The leukemia death rate in workers was not higher than the U.S. rate but was higher than the rate in county populations surrounding mills. Workers whose last jobs were in the finishing areas of the mills had an elevated SMR for liver cancer. An internal comparison of occupational characteristics indicated that workers employed in mills using other chemical pulping operations had significantly elevated mortality from all causes, all cancers, heart disease, lymphomas, and brain cancers. Lung cancer mortality was elevated in mills using kraft pulping. The internal comparisons confirmed the association between work in finishing and the risk of liver cancer. This study was designed to investigate whether pulp and paper mill workers have any risks that would indicate the need for studies detailing exposures.

Massive open online courses in public health.

Massive open online courses (MOOCs) represent a new and potentially transformative model for providing educational opportunities to learners not enrolled in a formal educational program. The authors describe the experience of developing and offering eight MOOCs on a variety of public health topics. Existing institutional infrastructure and experience with both for-credit online education and open educational resources mitigated the institutional risk and resource requirements. Although learners are able to enroll easily and freely and do so in large numbers, there is considerable variety in the level of participation and engagement among enrollees. As a result, comprehensive and accurate assessment of meaningful learning progress remains a major challenge for evaluating the effectiveness of MOOCs for providing public health education.

US army chemical corps Vietnam veterans health study: preliminary results

The long-term health consequences of exposure to phenoxyherbicides used in Vietnam has been a great concern to the veterans. In addition to the Air Force Ranch Hand personnel, Army Chemical Corps personnel who served in Vietnam are thought to have had some of the highest herbicide exposures. The Department of Veterans Affairs commenced a study of veterans who served in Vietnam as members of the Army Chemical Corps and a comparison cohort of Army Chemical Corps personnel who served elsewhere. A total of 2872 Vietnam veterans and 2737 non-Vietnam veterans who served in the Army Chemical Corps were identified for inclusion in a telephone health interview survey with a random 20% sample of veterans receiving serum dioxin and other congeners assessments. In a feasibility study which included 284 Vietnam veterans and 281 non-Vietnam veterans, 100 serum assessments were conducted of which 95 were included in the analysis. Vietnam veterans with a history of spraying herbicides were found to have a statistically significant elevation in their current serum 2,3,7,8-TCDD concentrations compared to non-Vietnam veterans without a spray history (P = 0.05). Other 2,3,7,8-substituted dioxins levels were comparable to the levels found in the non-Vietnam veterans. This feasibility study demonstrated that serum dioxin concentrations from a sample of the study participants can be used to identify exposure variables in the health survey that can serve as a surrogate measure of phenoxyherbicide exposure.

Knowledge and practice of dust mite control by specialty care.

BACKGROUND Dust mites are the primary indoor allergen risk for increasing asthma attacks and morbidity. Adherence to allergen avoidance recommendations decreases bronchial reactivity and asthma morbidity. OBJECTIVE This study compared the knowledge and practice of environmental control advice of families of children with asthma seen by an allergist or a pediatrician. Studies suggest that knowledge and practice of environmental control recommendations is inconsistent. METHODS Subjects were aged 6 to 17 years, diagnosed with asthma, and had positive skin test to dust mites. There were 114 eligible pediatric patients, and 69 had also seen an allergist before the study. An in-home evaluation was completed during which parents were asked about environmental control knowledge and practice. An environmental technician then completed a walk-through evaluation to observe which recommendations were implemented in the home. RESULTS Families who saw an allergist demonstrated significantly greater awareness of environmental control recommendations for dust mite allergens than those who had not. Knowledge and placement of allergen-proof mattress and pillow covers was significantly higher in these families. However, 30% of families who saw an allergist reported no knowledge of any environmental control recommendations for dust mites. Less than half of the allergist families (48%) who were advised to use mattress encasements actually had encasements on their childrens beds. CONCLUSIONS The parents of dust mite-sensitive, asthmatic children who saw an allergist were more aware of dust mite allergen control recommendations and made more indoor environmental changes.

Johns Hopkins Bloomberg School of Public Health OpenCourseWare

The need for public health knowledge is ever increasing, but the educational options have been limited to coursework delivered by academics to individuals who can afford the cost of tuition at public health institutions. To overcome this disparity, Johns Hopkins Bloomberg School of Public Health (JHSPH) has joined the Massachusetts Institute of Technology‐initiated OpenCourseWare (OCW) movement to publish and share its collection of course content with the public at no charge. The JHSPH OCW project began in 2005 with funding support from the Hewlett Foundation. Its publishing process was integrated into the school‐wide web supplement system for managing course content. To date, content from more than 60 graduate‐level courses has been published, drawing an average of 40,000 visitors per month. OCW provides resources for faculty and students, both within and outside JHSPH in their pursuit of public health education. An OCW Image Library was created to provide object‐level access to illustrations produced by JHSPH OCW to replace copyright‐protected images removed from faculty course materials. Internal support and external assistance are both essential for the success of an Open Educational Resources (OER) programme; JHSPH OCW would have been impossible without administrative buy‐in, faculty participation, an adaptable technology infrastructure, Hewlett Foundation funding, and shared wisdom from Massachusetts Institute of Technology. This is an ideal time for institutions to develop their own OER programmes, possibly by working with the OCW Consortium, through which institutions have access to the collective experience of existing OER producers.

Comparison of Personal Exposure Meter Placement for the Determination of Office Worker ELF Magnetic Field Exposures

This article compares extremely low frequency (ELF) magnetic field exposures measured by placing EMDEX Lite personal exposure meters (PEMs) at the head, chest, and waist level for a group of office workers. Twenty-three volunteers were solicited to wear three PEMs simultaneously; one was attached to a baseball cap worn on the head, one was attached to a band and worn around the neck (positioned on the chest), and one was worn in a belted pouch around the waist (positioned on the right side of the hip). The effect of PEM placement was evaluated by comparing full-shift average exposures and daily maximum or peak exposure. The results of this investigation indicate that time-weighted average magnetic field exposures determined at the hip provide the highest mean exposure estimates. Averages of the full-shift mean magnetic field measurements taken at hip and head levels were statistically greater than measurements taken at the chest level by 33 and 22%, respectively. Comparisons of the maximum or peak magnetic field exposures by body position indicate that the hip position produced an average exposure estimate that was 136% greater than the average head-level measurement. Results suggest that for office workers PEM meter placement on the body does not produce large differences in full-shift average ELF magnetic flux density exposures. However, the hip position produced the largest daily maximum or peak exposures. It is recommended that PEMs be placed on the hip for exposure assessments in office environments, because this placement is the most commonly used, the most convenient, and resulted in the highest magnetic field exposures.

Characterization of Extremely Low Frequency Magnetic Field Exposures of Office Workers

Abstract The purpose of this study is to present results of an extremely low frequency magnetic field exposure assessment performed in a large office building environment. The extremely low frequency magnetic field assessment strategy included an evaluation of full-shift personal exposure for building occupants, a determination of average work area magnetic fields, and magnetic field characterizations of sources within each work area. An employee questionnaire regarding daily utilization patterns of workplace magnetic field sources was also used to help interpret exposure information. Magnetic field exposures were determined using EMDEX magnetic field exposure meters. For personal magnetic field characterization, each participant wore the monitor for a full shift, and office area magnetic fields were determined as the average of five equally spaced measurements. In situ source characterization included measuring magnetic fields at 30 and 50 cm from pieces of electrical equipment. 259 employees in the buil...