The impact of housing type on low-income asthmatic children receiving multifaceted home interventions

OBJECTIVES

This study sought to evaluate whether government-assisted vs market-rate housing type influences the frequency of asthma symptoms or the quality of life scores among low-income urban children. In addition, the study sought to evaluate whether housing type influenced the success of in-home environmental and educational interventions in improving children's asthma symptoms or quality of life scores.

STUDY DESIGN

This was a before-and-after intervention design. Comprehensive health and environmental assessments and subsequent interventions were completed in 176 low-income households with 257 asthmatic children living in government-assisted housing and market-rate housing in Lowell, Massachusetts.

METHODS

We collected environmental and health data with questionnaires at a baseline and a 12-month follow-up visit using the Children's Health Survey for Asthma and a walk-through environmental checklist. Education, tools to remove asthma triggers from the home, and home repairs and remediation were included in the interventions.

RESULTS

As in other studies of multifaceted home interventions, there were significant improvements in all asthma symptoms, reductions in healthcare utilization related to asthma, and improvements in quality of life domains for children in both housing types. Environmental indices also improved from the baseline to the final assessment for both housing types. However, the housing type was an important factor in predicting a child's asthma status at the start of the study, with children living in government-assisted housing having significantly better physical health scores (76.8 of 100) and family emotional health scores (74.8 of 100) and fewer overnight hospital stays (mean of 0.02 in the previous 4 weeks) than children living in market-rate housing (67.6, 71.6, and 0.06, respectively). Examination of the change in the health status over the 1-year study period found that children living in market-rate housing had significantly larger reductions in the number of asthma attacks (0.43 in the previous 4 weeks versus 0.24 in assisted housing) and overnight hospital stays (0.06 in the previous 4 weeks versus 0.01 in assisted housing) and larger improvements in physical health quality of life scores (54% improved versus 25.5% in assisted housing).

CONCLUSIONS

Public assistance for low-income urban housing is associated with better health among children with asthma, and may influence the impact the in-home interventions have on health outcomes because children in market-rate housing have more prospects for improvement in their asthma-related health.

Estimation of compressive forces on lumbar spine from categorical posture data

To combine estimates of trunk posture and force into an integrated measure of load on the low back, continuous variables for body angles were estimated by assuming specified distributions within corresponding posture categories with Monte-Carlo (MC) simulation. The estimated posture angles were compared with reference measurements from the Lumbar Motion Monitor and inclinometers. The lumbar compression estimates, generated from simulated posture angles and from direct measurement, were compared. Trunk flexion showed high correlation between direct measurements and simulated angles, as did L5/S1 compression. The MC approach to extracting continuous posture angles from categorized observations did not appear to introduce large error in the variables used to estimate spinal compressive forces. When instrumentation methods of postural assessment are not feasible, a simulation approach combined with biomechanical modelling could be used to integrate multiple external exposure variables into estimates of compressive forces acting on the low back.

Short-term effects of formaldehyde on peak expiratory flow and irritant symptoms

The authors studied the respiratory effects of formaldehyde exposure among students who dissected cadavers in a gross anatomy laboratory. Peak expiratory flow and respiratory symptoms were measured before and after each weekly laboratory session. Each of 38 students was exposed to formaldehyde for 2.5 hr/wk for 14 wk. Individual, daily formaldehyde measurements averaged 1.1 ppm (standard deviation = 0.56 ppm). Multivariate models demonstrated two different time scales of effect of formaldehyde on peak expiratory flow: (1) exposure during the previous 2.5 hr reduced peak expiratory flow by -1.0% per ppm, and (2) average exposure during all preceding weeks reduced peak expiratory flow by an additional -0.5% per ppm of formaldehyde. However, the short-term exposure effect was diminished during the first 4 wk, suggesting at least partial acclimatization. Symptom reporting was also associated with exposure during the previous 2.5 hr, and similar evidence of acclimatization was observed. These results suggest that there are two different time scales of response to formaldehyde, and they emphasize the need for longitudinal studies, characterized by quantitative exposure characterization, and frequent measurements of outcome.

A nested case-control study of stomach cancer mortality among automobile machinists exposed to metalworking fluid

PURPOSE: In a nested case-control study of 140 stomach cancer deaths (1941-1984) among 46,384 automobile workers, we examined risk in relation to lifetime exposure to metalworking fluid (MWF) in machining and grinding operations.METHODS: Exposure was defined during varying windows of biologic time (<10 years before death, 10-20 years before death, and > 20 years before death) and evaluated using a nonparametric smoothing technique and conditional logistic regression. Exposure was measured by duration, intensity (mg/m(3)), and cumulative exposure (mg/m(3)-years) to each MWF type (straight, soluble, or synthetic), as well as by duration of exposure to selected metals, additives, and components of the fluids.RESULTS: When data from three plants were combined, grinding with water-based synthetic or soluble MWF increased the risk of stomach cancer mortality. Those grinding with synthetic MWF with more than 1.3 mg/m(3)-years exposure during the 10 years just prior to death experienced a 4.4-fold risk of stomach cancer (95% CI 1.5-13.1). Increased risk was also observed among those in the highest category of soluble grinding grading exposure (OR 1.9; 85% CI 1.0-3.6). In plant-specific analysis, there was evidence of increased risk of stomach cancer associated with exposure to straight MWF and iron, as well as the water-based fluids.CONCLUSIONS: Study findings suggest that stomach cancer mortality was associated with exposure to each MWF type. Results suggesting that synthetic MWF may act as a stomach cancer promoter are of particular concern because this MWF is widely used in today's high speed grinding operations.

A field investigation of the acute respiratory effects of metal working fluids. II. Effects of airborne sulfur exposures

An investigation of the acute respiratory effects of workers exposed to metal working fluids (MWF) was conducted in an automobile parts manufacturing facility. After observing an association between cross-shift decline in forced expiratory volume in the first second (FEV1) and aerosol mass concentration, improved characterization of the exposure was sought through investigation of four elements of a priori interest (Cl, Cr, Ni, S). Of these, only sulfur showed an association with cross-shift FEV1 decrement. The relative risk of 5% cross-shift FEV1 decrement was 2.7 (95% confidence interval = 1.0-6.0) comparing those with > 4.4 micrograms/m3 to those with < 2.5 micrograms/m3 sulfur exposure. Because the concentrations of sulfur in this environment were relatively low and other respiratory irritants were present, sulfur is more likely to be an indicator of more irritating conditions than the sole agent responsible for the observed acute respiratory effects.

A field investigation of the acute respiratory effects of metal working fluids. I. Effects of aerosol exposures

A study of cross-shift change in pulmonary function was conducted among workers exposed to metal working fluids (MWF) in an automobile parts manufacturing company. Three hundred eighty-six workers (216 machinists exposed to straight or soluble MWFs, and 170 nonmachinists) were studied for 1 day, performing spirometry at the beginning and end of their shift. Airborne concentrations of inhalable particulate, culturable bacteria, and endotoxin were measured. We observed an approximately threefold increase in the incidence of 5% or greater cross-shift decrement in forced expiratory volume during the first second among those with exposures above about 0.15 mg/m3, compared to those with exposures below about 0.08 mg/m3. There was some evidence that chronic respiratory symptoms were more prevalent among machinists than among nonmachinists, notably for chronic cough. Baseline FEV1 was about 3% lower on average among those with soluble MWF exposure compared to nonmachinists. These findings are consistent with earlier studies showing respiratory effects of MWFs.

A field investigation of the acute respiratory effects of metal working fluids. II. Effects of airborne sulfur exposures

An investigation of the acute respiratory effects of workers exposed to metal working fluids (MWF) was conducted in an automobile parts manufacturing facility. After observing an association between cross-shift decline in forced expiratory volume in the first second (FEV1) and aerosol mass concentration, improved characterization of the exposure was sought through investigation of four elements of a priori interest (Cl, Cr, Ni, S). Of these, only sulfur showed an association with cross-shift FEV1 decrement. The relative risk of 5% cross-shift FEV1 decrement was 2.7 (95% confidence interval = 1.0-6.0) comparing those with > 4.4 micrograms/m3 to those with < 2.5 micrograms/m3 sulfur exposure. Because the concentrations of sulfur in this environment were relatively low and other respiratory irritants were present, sulfur is more likely to be an indicator of more irritating conditions than the sole agent responsible for the observed acute respiratory effects.

Neurobehavioral effects of acute styrene exposure in fiberglass boatbuilders

A field investigation of the effects of acute exposure to styrene among fiberglass boatbuilders was performed. Personal samples of styrene in breathing zone air and postshift urinary mandelic acid were collected for 105 workers exposed and not exposed to styrene in 6 fiberglass boatbuilding companies in New England. Three tests from the computerized Neurobehavioral Evaluation System (NES) were performed by the subjects in the morning before exposure to styrene, near midday, and at the end of the work day. Duration of exposure averaged 2.9 years (SD = 4.6), 8-hour TWA styrene exposure averaged 29.9 ppm (SD = 36.2), and urinary mandelic acid averaged 347 mg/g creatinine (SD = 465). Regression analyses indicated a statistically significant relationship between postshift performance on the Symbol-Digit test and both acute styrene exposure and mandelic acid. Other analyses comparing workers exposed to less than 50 ppm and greater than 50 ppm styrene also showed a significant effect on Symbol-Digit performance. All three NES tests showed test-retest correlation coefficients above .80, and ease of use for collection of neurobehavioral data under field conditions was demonstrated.

Diesel exposure and mortality among railway workers: results of a pilot study

A pilot study of the mortality of railway workers was undertaken to evaluate the feasibility of studying the association of exposure to diesel exhaust and cause specific mortality. The cohort consisted of 2519 white male subjects aged 45-64 with at least 10 years of railway service by 1967. Subjects were selected on the basis of job classification, and cause specific mortality was ascertained for subjects who died (n = 501) up to 1979. The total follow up period was 28.4 (X 1000) person-years. The standardised mortality ratio (SMR) for the cohort, based on United States national rates, was 87 (95% confidence limits 80, 95), and there were no significant differences from expected number of deaths for any specific neoplasm. The directly standardised rate ratio for respiratory cancer among diesel exposed subjects relative to unexposed subjects was 1.42 +/- 0.50 (means +/- SE). A proportional hazards model was consistent with the findings of the standardised rate ratio, but in neither analysis was the increased risk of respiratory cancer in diesel exposed subjects statistically significant.