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G G Rhoads

Publications and source records attributed to G G Rhoads.

138 records · Page 8Linked to original sources
PubMedDate not supplied

A field comparison of two methods for sampling lead in household dust.

Comparability of dust lead measurements has been a difficult problem due to different sampling and analysis techniques. This paper compares two dust sampling techniques, the U.S. Department of Housing and Urban Development (HUD) dust wipe method and the Lioy, Wainman, Weisel (LWW) sampler. The HUD method specifies using a moist towelette to pick up as much dust as possible in a specified area and estimates total lead loading. The LWW sampler collects the dust on preweighed wetted filter media, and provides greater standardization of the sampling path and pressure applied. LWW samples were analyzed using inductively coupled plasma mass spectronomy (no samples below minimum detection limit), while HUD samples were analyzed using flame atomic absorption (32% of samples below minimum detection limit). A bootstrapping technique was used in the analysis to contend with those HUD samples below the minimum detection limit. Mixed model equations were generated to predict HUD values from LWW results, and to examine the effects of sampling location, time, and method. The results indicate that the two samplers performed similarly under field conditions, although the LWW sampler produced consistently lower lead loading estimates. LWW values that predicted HUD lead clearance values of 100 micrograms/ft2 for floors and 500 micrograms/ft2 for window sills were 72 micrograms/ft2 and 275 micrograms/ft2, respectively. To examine internal reproducibility, duplicate samples were taken using both the HUD and LWW methods. Correlation results within paired samples indicated a statistically significantly higher (p < 0.001) internal reproducibility for lead loading, for the LWW sampler (r = 0.87), than for the HUD method (r = 0.71). Some of the differences appeared to be related to the analytical methods.

Child, Preschool↗
PubMedDate not supplied

Risk of abruptio placentae by region of birth and residence among African-American women in the USA.

OBJECTIVE: To determine whether Southern-born African-American women have higher incidence of abruptio placentae, irrespective of their region of residence. METHODS: For this retrospective cohort study we used vital statistics data of the US for the years 1995 and 1996. Age-adjusted rates of abruption were derived for combinations of regions of birth (Northeast, Midwest, South, West, and Foreign-born) and regions of residence (Northeast, Midwest, South, and West) for all singleton live births among African-American women. RESULTS: The incidence of abruptio placentae among African-American women was 6.7 per 1,000 live births. The age-adjusted rates of abruption among women who had not migrated showed that those in the Northeast had the highest rates (8.3 per 1,000), followed by those in the Midwest (6.3 per 1,000), South (6.0 per 1,000) and in the West (4.9 per 1,000). The prevalence of risk factors showed the same pattern. CONCLUSION: The results of the study suggest that place of residence rather than place of birth was associated with the risk of placental abruption. However, foreign-born African-American women had lower rates of abruption irrespective of the region of residence.

Abruptio Placentae↗
PubMedDate not supplied

Serum triglyceride and risk of coronary heart disease, stroke, and total mortality in Japanese-American men.

The role of serum triglyceride as a risk factor for coronary heart disease (CHD), stroke, and total mortality was examined in men of Japanese ancestry who were 45 to 78 years old. During the first 10 years following a baseline nonfasting triglyceride determination, there were 490 incidence cases of CHD in 7615 men at risk. Average annual incidence rates were 2.1 times higher in men with nonfasting values above the 75th percentile (279 mg/dl) than in those under the 25th percentile (129 mg/dl, p less than 0.001). This association largely disappeared when associations of triglyceride with other CHD risk factors were accounted for. Fasting triglycerides were measured in a representative sample of 1729 men part-way through the study. With an average follow-up of 5.7 years there were 72 new CHD cases in this group with the risk for men in the top quartile (above 195 mg/dl) being 1.9 times higher than for those in the bottom quartile (below 94 mg/dl). This gradient was of borderline significance (p less than 0.10) and completely disappeared in a multivariate analysis which included HDL and other factors. It appears that the association of triglyceride with CHD in this cohort is of a noncausal nature. Triglycerides were not predictive of stroke or of total mortality in these men.

Aged↗
PubMedDate not supplied

Factors related to stroke incidence in Hawaii Japanese men. The Honolulu Heart Study.

As part of an ongoing longitudinal study of coronary heart disease and stroke among Japanese men in Hawaii, 8,006 men of Japanese ancestry living on the island of Oahu and aged 45-68 at entry examination have been followed by reexamination and surveillance. One hundred and eleven were found to have evidence of prior stroke at the time of the initial examination. During a six-year follow up period of the remaining 7,895 men, 94 developed definite thromboembolic stroke, 33 definite intracranial hemorrhage, and 6 developed stroke of unknown type. The principal risk factors for thromboembolic stroke were: elevated blood pressure, glucose intolerance, age, and electrocardiography evidence of left ventricular hypertrophy or strain. Attributes associated with increased risk of intracranial hemorrhage were elevated blood pressure, electrocardiographic evidence of left ventricular hypertrophy or strain, and alcohol intake. Serum cholesterol level was negatively associated with risk of intracranial hemorrhage.

Age Factors↗
PubMedDate not supplied

Incidence of transient cerebral ischemic attack in Hawaii Japanese men. The Honolulu Heart Study.

At the Honolulu Heart Study 7,895 men of Japanese ancestry, 45--68 year-old, who were free of previous stroke at the baseline examination (1965--1968) were followed 6 years for the development of transient cerebral ischemic attacks (TIA). Fifty-one men developed probable or possible episodes. In multivariate analysis TIA was associated with preceding hypertension, cigarette smoking and coronary heart disease. It was less common in men who were facile with written Japanese language, in those who consumed alcohol, and in those who were physically active. During an average follow up of 3 years after these TIA events 2 strokes occurred, vs 0.7 expected. This prognosis is more favorable than that reported by other studies.

Aged↗
PubMedDate not supplied

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: incidence of stroke in Japan and Hawaii.

As part of the Ni-Hon-San Study, stroke incidence was compared in the Japan and Hawaii cohorts. Stroke cases were classified in two types, intracranial hemorrhage (ICH) and thrombo-embolic stroke (T-E). For each type the incidence in Japan was about three times as great as in Hawaii. The ratio ICH/T-E was 1/2.2 and 1/1.6 in Japan and Hawaii, respectively. Blood pressure was the most important risk factor, followed by age for total stroke in both Japan and Hawaii. Proteinuria was also a risk factor in Hawaii. Conversely, an index of animal food intake was inversely related to total stroke, significantly in Hawaii, and at a suggestive level for total and hemorrhagic stroke in Japan. Since the levels of blood pressure do not differ between Japan and Hawaii, one possible explanation for the large difference in stroke incidence between the two cohorts may be the fact that animal protein and saturated fat intake, which is inversely associated with stroke incidence, is much greater in Hawaii than in Japan. This explanation would support epidemiologic and experimental studies in Japan which suggest that dietary animal protein and fat exert an inhibitory effect on the incidence of stroke.

Age Factors↗
PubMedDate not supplied

Risk factors related to ischemic and hemorrhagic cerebrovascular disease at autopsy: the Honolulu Heart Study.

This study of cerebrovascular lesions at autopsy among Hawaiian Japanese men identifies similar risks factors for cerebral infarction and hemorrhage that have been identified in a previous incidence study. Demonstrated differences were essentially the same whether subjects with these tissue changes were compared to men showing no central nervous system disease at autopsy or when they were compared with men still alive. Cerebral infarcts accompanied myocardial infarction (CHD) in 58% of autopsy cases and were associated with CHD risk factors (high serum cholesterol, hypertension, severe atherosclerosis of the coronary arteries and aorta). These associations did not persist when CHD cases were removed from the analysis, indicating there were two subsets of men with cerebral infarction. Hypertension was strongly associated with hemorrhagic disease, as were cigarette use and alcohol consumption.

Asian↗
PubMedDate not supplied

Dietary and other risk factors for stroke in Hawaiian Japanese men.

As part of an on-going longitudinal study, 7895 men of Japanese ancestry living on the island of Oahu, aged 45-68 and free of evidence of prior stroke at entry examination, have been followed by re-examinations and surveillance. During ten years of follow-up 154 men developed thromboembolic stroke, 65 developed intracranial hemorrhage, and 19 developed stroke of unknown type. There were 79 deaths attributed to stroke. The independent risk factors for thrombo-embolic stroke were elevated blood pressure, glucose intolerance, age, electrocardiographic evidence of left ventricular hypertrophy or strain, cigarette smoking and proteinuria. Attributes associated with increased risk of intracranial hemorrhage were age, elevated blood pressure, cigarette smoking, serum uric acid and, inversely, serum cholesterol level. Electrocardiographic evidence of left ventricular hypertrophy or strain significantly increased the risk of cerebral hemorrhage, but was not associated with subarachnoid hemorrhage. In univariate analysis, there was an inverse relation between dietary fat intake and thrombo-embolic and total stroke incidence. An inverse relation was also shown between protein intake and total stroke incidence. These dietary relations became statistically not significant in multivariate analysis. No relation was found between salt intake and the incidence of stroke.

Age Factors↗
PubMedDate not supplied

Recent trends in cesarean birth and trial of labor rates in the United States.

A national probability survey was conducted to evaluate changes since 1979 in cesarean delivery and trial of labor rates after a previous cesarean delivery. Questionnaires were mailed to 538 hospitals and 87% responded. In 1979, of women with a prior cesarean birth 2.1% (+/- 0.3%) were given a trial of labor. By 1984, the rate increased fourfold to 8.0% (+/- 0.7%). Trials of labor increased dramatically with the size of the delivery service. The rates ranged from 2% in smaller hospitals to 25% in larger hospitals. More than 50% of the trials of labor were successful. However, the fraction of hospitals with no trials of labor remains high (54%). Cesarean birth rates increased from 14.1% (+/- 0.1%) in 1979 to 19.0% (+/- 0.2) in 1984. Hospitals with fewer births had a larger variation in cesarean birth rates; the fifth and 95th percentiles were 5% and 33%, respectively, for hospitals with fewer than 500 deliveries per year, and 14% and 31% for hospitals with 1000 deliveries or more per year. Fetal distress accounted for a larger proportion of primary cesarean deliveries in 1984 (21%) compared with 1979 (14%). The observed increase in the rate of trial of labor does not seem to be large enough to stem the rising cesarean delivery rate. This survey and other national surveys provide no evidence that the cesarean delivery rates are leveling off or decreasing.

Cesarean Section↗
PubMedDate not supplied

The effectiveness of a home cleaning intervention strategy in reducing potential dust and lead exposures.

The changes in dust loading, lead loading and lead concentration, determined from vacuum samples and wipe samples collected during the Childhood Lead Exposure Assessment and Reduction Study (CLEARS) were analyzed to determine the efficacy of the cleaning protocol in homes of children found to have moderate lead poisoning, e.g. levels between 10-20 micrograms/dL. The samples were collected at least twice, and in 65 homes three times, during the course of a year long intervention in homes where half were randomized into a group which received a standardized Lead Intervention program for lead reduction, and the other homes only received an Accident Intervention program. The homes with lead burdened children were located in Hudson County, New Jersey (primarily in Jersey City), and were referred to the CLEARS by a number of private and public sources. Each home had wipe sampling conducted with the LWW Sampler (patented), and vacuum sampling was completed using a device described by Wang et al. in Applied Occupational and Environmental Hygiene. The results were compared in two ways: (1) between the two intervention groups, and (2) over the time course of the intervention period. When compared to the values seen in the first visit vacuum sampling results showed statistically significant decreases in lead loading and dust loading by the third sampling visit for the Lead Intervention homes. Substantial reductions in lead loading and dust loading were also seen when the Lead Intervention values were compared to values obtained in the Accident Intervention homes over the course of the year long intervention. The wipe sampling results for the 65 homes with three visits found no significant reductions in dust loading and lead loading among any of the room surfaces sampled in the Accident Intervention homes. There were 75% and 50% reductions observed on the window sills and on the bedroom floors of the homes which participated in the Lead Intervention. The levels in the living room and the kitchen showed very little change in loadings. This appeared to be due to the fact these rooms were near a background or baseline value of 0.3 g/cm2 and 0.12 mg/cm2 for dust loading and lead, respectively. This was substantiated by the window sills and bedroom wipe sampling results since each surface approached these values by the third visit. Significant reductions in lead concentrations found in the wipe samples from the intervention homes appeared to be related to the absence of historically active sources of lead in these homes, rather than elimination of current sources. The results of the micro-environmental sampling program in CLEARS indicated that a year long cleaning protocol can significantly decrease lead levels in rugs and on other exposed surfaces. This will reduce the potential for exposure to lead among the occupants, especially children, that come in contact with such surfaces.

Air Pollution, Indoor↗