Iron deficiency associated with higher blood lead in children living in contaminated environments.

The evidence that iron deficiency increases lead child exposure is based primarily on animal data and limited human studies, and some of this evidence is contradictory. No studies of iron status and blood lead levels in children have accounted for environmental lead contamination and, therefore, the source of their exposure. Thus, no studies have directly determined whether iron deficiency modifies the relationship of environmental lead and blood lead. In this study, we compared blood lead levels of iron-deficient and iron-replete children living in low, medium, or highly contaminated environments. Measurements of lead in paint, soil, dust, and blood, age of housing, and iron status were collected from 319 children ages 1-5. We developed two lead exposure factors to summarize the correlated exposure variables: Factor 1 summarized all environmental measures, and Factor 2 was weighted for lead loading of house dust. The geometric mean blood lead level was 4.9 microg/dL; 14% exceeded 10 microg/dL. Many of the children were iron deficient (24% with ferritin < 12 ng/dL). Seventeen percent of soil leads exceeded 500 microg/g, and 23% and 63% of interior and exterior paint samples exceeded 5,000 microg/g. The unadjusted geometric mean blood lead level for iron-deficient children was higher by 1 microg/dL; this difference was greater (1.8 microg/dL) after excluding Asians. Blood lead levels were higher for iron-deficient children for each tertile of exposure as estimated by Factors 1 and 2 for non-Asian children. Elevated blood lead among iron-deficient children persisted after adjusting for potential confounders by multivariate regression; the largest difference in blood lead levels between iron-deficient and -replete children, approximately 3 microg/dL, was among those living in the most contaminated environments. Asian children had a paradoxical association of sufficient iron status and higher blood lead level, which warrants further investigation. Improving iron status, along with reducing exposures, may help reduce blood lead levels among most children, especially those living in the most contaminated environments.

Physician reports of work-related asthma in California, 1993-1996.

BACKGROUND: Work-related asthma is a leading cause of occupational respiratory illness. METHODS: Work-related asthma was studied in California over a 36-month period, from March 1, 1993 to February 29, 1996. The surveillance system identified cases from Doctor's First Reports (DFRs), a mandated physician reporting system. Structured follow-up telephone interviews of DFR asthma cases were conducted to collect work history, exposure, and medical information. Statewide employment data was used to calculate disease rates among industry groups. RESULTS: Based on 945 cases of work-related asthma, the average annual reporting rate for work-related asthma in California was 25/million workers. We estimate that the actual rate is 78/million, adjusted for likely underreporting. Janitors and cleaners (625/million) and firefighters (300/million) had the highest reporting rates of work-related asthma. Half of all work-related asthma cases were associated with agents not known to be allergens. CONCLUSIONS: A greater proportion of work-related asthma associated with irritant exposures was identified than has previously been reported. The surveillance data provide a very conservative estimate of the incidence of work-related asthma.

The Friday afternoon pulmonary angiogram: temporal relationship between onset of symptoms and requests for angiography.

BACKGROUND: To determine if pulmonary embolism symptoms and pulmonary angiography have a proclivity for a particular day of the week, month or season (Part I) and to assess the length of time elapsing between the appearance of symptoms and requests for pulmonary angiography (Part II). DESIGN: Prospective (in part) collection of data and retrospective review of clinical records. SETTING: Large metropolitan, university affiliated hospital. METHODS: Part I: 2,969 consecutive pulmonary angiograms performed over 17 years, were collected according to the day of the week, month and season of their performance. Relevant rates were calculated. Part II: A study of the time interval between the onset of pulmonary embolism symptoms and requests for and performance of angiography was conducted in 128 patients. Results. Part 1. In the course of 17 years, more pulmonary angiograms were performed on Fridays (mean 37.2, SE 1.8), than on any other day of the week (p <.001). No proclivity for a particular month or season was observed. Part II. The mean time elapsed between the onset of symptoms and requests for angiography was 24 hours (range 0.2-162, SE 4.3) for inpatients, and 45 hours (range 3-358, SE 7.8) for outpatients. The angiogram was completed urgently, within two hours of the onset of symptoms, only in 2.4%. CONCLUSIONS: Pulmonary angiography has a proclivity for Fridays. Pulmonary embolism symptoms and consequent angiograms do not favour a specific day, month or season. In most cases the time elapsing between the onset of symptoms and requests for angiography is too long to be consistent with urgency. The frequent Friday pulmonary angiogram reflects a tendency to "mop up" unfinished business prior to the week's end.

Nationwide telecare for diabetics: a pilot implementation of the HOLON architecture.

This paper presents results from a demonstration project of nationwide exchange of health data for the home care of diabetic patients. A consortium of industry, academic, and health care partners has developed reusable middleware components integrated using the HOLON architecture. Engineering approaches for multi-organization systems development, lessons learned in developing layered object-oriented systems, security and confidentiality considerations, and functionality for nationwide telemedicine applications are discussed.

Lead levels in the household environment of children in three high-risk communities in California.

To assess environmental lead contamination in the household environment of children in high-risk areas of California, three urban locations were surveyed by the California Department of Health Services. Plant, soil, and dust lead levels were measured and a questionnaire was administered. This survey estimates that 3 million homes in California (27%) may have exterior paint lead levels > or = 5000 ppm, and 1.3 million homes (12%) may have interior paint lead levels > or = 5000 ppm. The highest concentrations of lead in paint were found on exterior surfaces and, for homes built between 1920 and 1959, on trim. Age of housing was the best predictor of lead in soil and dust; homes built before 1920 were 10 times more likely to have soil lead levels > or = 500 ppm compared to post-1950 homes. Most of the variability in dust lead levels could not be explained by factors measured in this survey. Sources of lead in the home were more highly correlated with lead dust concentration levels than they were with lead dust loading levels. Households with members reporting a lead job were twice as likely to have high dust lead levels compared to households with no one reporting a lead job. The significant differences in dust lead concentration levels between communities were not reflected in differences in dust lead loading levels. Measuring dust lead loading levels does not appear to be a meaningful sampling method for risk assessment in the context of prioritizing abatement.