Removal of phosphorus from trickling filter effluent by electrocoagulation.

As regulatory requirements for contaminants in wastewater discharged to the environment get stricter, alternative or additional treatment processes to those already being used are necessary. One contaminant of particular concern associated with discharging treated municipal wastewater to a receiving water body is phosphorus (P). A continuous scale electrocoagulation (EC) system was investigated as an alternative to conventional chemical addition for P removal from municipal wastewater. The EC process was optimized for iron dose delivery by changing the electrical current, electrode spacing and the reactor contact time, and a comparison was made with conventional ferric dosing through jar testing. Results showed that EC could achieve P removal to meet a P consent of 1 mg L⁻¹ at a dose of 154 mg L⁻¹ Fe. The process was shown to provide a supplementary benefit for chemical and biological oxygen demand removal of 86% and 82%, respectively, but gave no significant removal of other sanitary pollutants. When compared directly with conventional iron dosing, EC required approximately twice the iron dose. When electrical costs were also factored into the comparison, EC was shown to be approximately double the cost of conventional dosing and at present is not a feasible alternative to conventional coagulation using ferric chloride.

Patient weighting of osteoporosis medication attributes across racial and ethnic groups: a study of osteoporosis medication preferences using conjoint analysis.

UNLABELLED: We studied the ranking of osteoporosis (OP) medication attributes in a convenience sample of four different racial/ethnic groups in the United States. Our study showed that postmenopausal women differ in the ranking of OP medication attributes based on age, educational level, income, and prior fracture history. INTRODUCTION: Decision making about OP medication-related behavior relies heavily on patient preferences about specific medication attributes. Patients may decide to initiate, change, or stop therapies based on ranking of perceived attributes of the therapy and their personal attitudes toward those attributes. We used MaxDiff, a form of conjoint analysis (Ryan and Farrar 2000), to explore patient weighting of attributes across four racial/ethnic groups at two sites in the United States and defined four critical attributes that influence such decisions (safety, efficacy, cost, and convenience) from qualitative interviews. METHODS: We recruited a sample of 367 Postmenopausal (PM) women at risk of OP fractures from four racial/ethnic groups: Caucasian (n = 100), African American (n = 100), Asian American (n = 82), and Hispanic American (n = 85). Respondents completed a laptop-based questionnaire that included demographic items, several short scales on medical care preference and OP patient perceptions, and a MaxDiff procedure that determines comparative ranking of attributes either as least important or most important to their decisions. RESULTS: MaxDiff analyses were done to evaluate the relative weight of specific statements for each participant and to determine whether racial/ethnic groups differed across dimensions. Overall, participants in all four groups rated efficacy > safety > cost > convenience. CONCLUSIONS: Although there were no significant differences among the racial/ethnic groups on overall ranking of attributes, subgroup analyses revealed significant impact of age, education, income, and prior fracture on these decisions. The findings from this study suggest that postmenopausal women differ in their ranking of OP medication attributes, and healthcare providers must account for personal preferences in their communication about and selection of OP medications.

Inpatient palliative medicine is evidence based.

Specialist palliative care services have previously been studied to see whether their intervention is of benefit. However, there is a lack of data on whether interventions in individual palliative care units are evidence based. This study looked at 32 problems and 114 interventions over 1 month in January 2000 in an inpatient palliative care unit. These interventions were then researched to see if there had been trials showing their benefit. The results were then classified: 81% were evidence based (randomized controlled trials 48%, evidence from other trials 27%, convincing non-experimental evidence 6%). This compares favourably with studies performed in other areas of medicine.

Hip protectors improve falls self-efficacy.

OBJECTIVES: To investigate the effect of use of external hip protectors on subjects' fear of falling and falls self-efficacy (belief in their own ability to avoid falling). DESIGN: Randomized controlled trial. SETTING: Aged-care health services in Sydney, Australia. PARTICIPANTS: 131 women aged 75 years or older, who had two or more falls or one fall requiring hospital admission in the previous year and who live at home. Sixty-one subjects were in the intervention group and 70 in the control group. INTERVENTION: Use of external hip protectors and encouragement to use the protectors by an adherence nurse. MEASUREMENTS: At the time of enrolment into a wider study examining the effect of hip protectors on hip fractures, participants recruited at home completed an assessment of fear of falling and falls efficacy as measured by the Falls Efficacy Scale and the Modified Falls Efficacy Scale. At 4-month follow-up, these scales were readministered by an observer who was not aware of the allocation of the participant to intervention or control groups. RESULTS: Fear of falling and falls self-efficacy, as measured by the Falls Efficacy and Modified Falls Efficacy Scales, were similar at baseline in both groups. Fear of falling was present at follow-up in 43% of subjects using hip protectors and 57% of the control group (chi2 = 2.58, P = 0.11). Hip protector users had greater improvement in falls self-efficacy at follow-up as measured by the Falls Efficacy Scale (t = 2.44, P = 0.016) and the Modified Falls Efficacy Scale (t = 2.08, P = 0.039). CONCLUSION: Hip protectors improve falls self-efficacy. As users of hip protectors feel more confident that they can complete tasks safely, they may become more physically active and require less assistance with activities of daily living.

Dog bite injuries in children: a preliminary survey.

Dog bite injuries in children are a preventable health problem. To characterize this type of injury, we have undertaken to define demographic criteria and patterns of injury inflicted by dogs in our pediatric population. A retrospective chart review was conducted of pediatric patients with dog bite injuries admitted to a Level I pediatric trauma center from January 1986 through June 1998. Patient demographics, canine characteristics, and hospital patient data were collected and analyzed using the Excel program and appropriate statistical methodology. There were 67 patient records reviewed. Thirty-eight (57%) of the patients were male, and 29 (43%) were female. There were 43 (64%) white children, 22 (33%) African-American children, and 2 (3%) Hispanic children. The average age of the children was 6.2 +/- 4.2 years, with an average weight of 23.3 +/- 13.7 kg. More than half the attacks occurred in the afternoon and 55 per cent of these attacks were documented as "unprovoked" attacks. Thirty-one (46%) of these attacks involved family pets, and 30 (45%) dogs were known to the attacked child. The head and neck was involved in greater than 67 per cent of these injuries. Pit bulls caused 25 per cent of the bite injuries. Large dogs were responsible for 88 per cent of the attacks. Forty-four (66%) patients required operative intervention. Twenty-eight of these patients had multiple anatomical areas injured. There were 44 procedures involving the head and neck, 21 involving extremities, and 6 involving other areas of the body. All patients 5 years of age and under had head and neck injuries. Dog bite injuries requiring admission occur more in male children. Caucasian and African American children were the majority of children affected. The children under 5 years of age suffered the most devastating injuries. More than half of these attacks were not provoked. More than two-thirds of the injuries to these children involved the head and neck. We conclude that effective prevention strategies must stress careful supervision of young children and the family or neighbor's dog, a scenario that may easily lead to complacency and set the stage for a severe injury.

Carpal development and morphology in archontan mammals.

Carpal morphology and development in bats, colugos, tree shrews, murids, and sciurids were studied in order to homologize carpal elements. Prenatal coalescence of discrete cartilaginous templates with a loss of a center of ossification appears to be the most common method of reducing carpal elements in these mammals. Only bats and colugos showed postnatal ossification between discrete elements as a method of reducing carpal elements. Carpal morphology of tree shrews is more diverse than previously reported. Ptilocercus shows a highly derived carpal morphology that may be related to its relatively greater arboreality. Dendrogale exhibits what is most likely the ancestral tupaiid carpal morphology. Carpal morphologies of Tupaia, Urogale, and Anathana are identical to each other. Carpal morphology differs between megachiropterans and microchiropterans. These differences may be related to different aerodynamic constraints between the suborders. The carpal morphology of microchiropterans is diverse and may reflect different adaptive regimes between microchiropteran families. Carpal morphology of the colugos shows both megachiropteran and microchiropteran characters. The function of these characters in colugos and bats (stabilization of the carpus in dorsiflexion) is proposed to be similar, although the locomotor roles may be quite different between these taxa.

Mortality in a cohort of pentachlorophenol manufacturing workers, 1940-1989.

Mortality in a cohort of 770 workers with potential pentachlorophenol (PCP) exposure was evaluated from 1940 through 1989. The study cohort is a subset of a larger cohort of workers with potential exposure to higher chlorinated dioxins. Total mortality and cancer mortality in the PCP cohort were slightly lower than expected in comparison to the U.S. white male population. There were 229 total deaths with 242.5 expected (SMR = 94, 95% confidence interval 83-108), and 50 cancer deaths with 52.6 expected (SMR = 95, 95% confidence interval 71-125). In comparison with unexposed employees, the risk ratio for total mortality was 1.03 (95% confidence interval 0.90-1.17), and the risk ratio for all cancer mortality was 0.95 (95% confidence interval 0.71-1.26). In most cause of death categories of a priori interest no deaths were observed in the cohort. A small excess of other and unspecified lymphopoietic cancer deaths was observed but did not appear to be related to exposure. Excesses of deaths due to cancer of the kidney, gastric and duodenal ulcer, cirrhosis of the liver, and all accidents were observed in comparison with the U.S. white male population and with unexposed employees. These were associated with increasing estimated cumulative PCP exposure after lagging exposures by 5 and 15 years. Despite the limited size and the generally favorable total mortality experience of the cohort, it was concluded that cohort members may have incurred increased risk of death due to some specific causes. The risks could not, however, be attributed conclusively to PCP exposure and may have been associated with other occupational and nonoccupational factors. Additional mortality surveillance of this cohort will be performed.

Update of the mortality experience of employees with occupational exposure to 1,2-dibromo-3-chloropropane (DBCP).

DBCP (1,2-dibromo-3-chloropropane), a nematocide, was used in the United States from the mid-1950s until 1977. The U.S. Environmental Protection Agency (EPA) restricted and eventually banned its use after the 1977 discovery of DBCP-induced sterility in production workers. The present study is an update of the mortality (1957-1989) experience of a cohort of 548 male employees who had potential for exposure in the production and formulation of DBCP. While adjusting for age, calendar-year, and pay status of all other Midland-area Dow Chemical male employees, there were 68 total observed deaths in the cohort compared to 72.1 expected (Mantel Haenszel Relative Risk 0.9, 95% Confidence Interval 0.7-1.2) and 19 deaths from all malignancies compared to 19.0 expected (RR 1.0, 95% CI 0.6-1.6). Of the a priori anatomic cancer sites of interest, there were no deaths from stomach, liver, kidney, testes, or nasal cavity cancers. Altogether, there were 7 deaths from lung cancer compared to 6.6 expected (RR 1.1, 95% CI 0.5-2.3). Among the 81 employees with exposure categorized as direct for 1 or more years, there were 3 observed lung cancer deaths compared to 0.9 expected (RR 3.3, 95% CI 1.1-9.6). Smoking was a confounding factor in the interpretation of this observation. Although the present analysis nearly doubled the number of person-years from the original study, the conclusions remain limited by the cohort's size and duration of follow-up.

Locomotion in captive Leontopithecus and Callimico: a multimedia study.

Video studies, gait analysis, footprint tracks, and observational scan sampling show that, in comparably furnished enclosures, Leontopithecus rosalia and Callimico goeldii are superficially similar in their use of predefined locomotor patterns but differ profoundly in many underlying details which reflect differences in postcranial morphology. Each uses pronograde arboreal quadrupedal walking, quadrupedal bounding, and vertical climbing with comparable frequency, and both shift to bounding while moving quadrupedally at high speeds. In walking, both species use a diagonal sequence gait. However, in Callimico the distance per bout traveled while walking or running is shorter than in L. rosalia and there is an emphasis on leaping (from a stationary position) and bounding-leaps (saltational extensions of pronograde quadrupedalism), in contrast with the basically quadrupedal style of L. rosalia. This dichotomy is consistent with anatomical specializations, such as forelimb elongation in Leontopithecus and hindlimb elongation in Callimico. In vivo hand- and footprint studies demonstrate grasping halluces in both species while walking. Limb stances in L. rosalia during "transaxial bounding" involve an overstriding hindlimb, a predominance of oblique rather than in-line travel, and unique hand and foot positions. Anatomically, this locomotor style may be associated with reduced dexterity of the elongate hands and a relatively short hallux. The captive locomotor profiles for both species probably reflect biased samples of the locomotor repertoire of their wild counterparts. Nevertheless, these data reflect species-specific integrations of locomotor behavior and morphology, and corroborate expectations of locomotor diversity among callitrichine primates, even those of similar body size. It is suggested, however, that conventional quantitative studies of locomotor profiles may prove inadequate for resolving subtle aspects of locomotor morphology and behavior.

Retrospective cohort mortality study of workers with potential exposure to epichlorohydrin and allyl chloride.

Previous epidemiologic research has associated potential epichlorohydrin exposure with lung cancer and, in conjunction with allyl chloride exposure, to heart disease mortality. The study was designed to test both hypotheses by examining the mortality experience of 1,064 male employees (12,574 person-years) who had a minimum of 1 month work experience between 1957-1986 in the production or use of epichlorohydrin and allyl chloride and 1 year total employment duration at Dow Chemical's Texas Operations. Vital status follow-up occurred through 1989 of which there were 66 total deaths (standardized mortality ratio [SMR] = 80, 95% confidence interval [CI] 62-101). There were no significantly elevated SMRs for all malignant neoplasms, lung cancer, circulatory system disease, or arteriosclerotic heart disease when compared to external (U.S.) or internal (Texas Operations) populations. There were no apparent mortality trends with cumulative exposure analyses of potential epichlorohydrin exposure with and without accompanying allyl chloride exposure. A high prevalence of circulatory system death certificates were certified by nonphysicians in the local county and more than one third were described in nonspecific terms. The study results are not consistent with the prior hypothesized associations. However, the study results are limited by the cohort's size, duration of follow-up, relatively few number of observed and expected deaths, and the level of potential epichlorohydrin exposure experience.

A phase II evaluation of tamoxifen in unresectable or refractory meningiomas: a Southwest Oncology Group study.

Twenty-one patients with nonresectable refractory meningiomas were registered on a study giving tamoxifen 40 mg per M2 b.i.d. for four days, then 10 mg b.i.d. thereafter. Nineteen were eligible and evaluated for response. One patient (5%) achieved an MRI-documented partial response while two had a minor response measured on CT scan which was of short duration (4 and 20 months). Six patients (32%) remained stable for a median duration of 31 + months while ten (53%) demonstrated progression. Twenty-two percent (22%) reported subjective improvement though this did not correlate with objective improvement in all cases. At present, a definite recommendation for the use of tamoxifen in refractory meningiomas cannot be made. Further evaluation of hormonal therapy of meningiomas with a consensus for definition of endpoints for evaluation of response in view of the difficulty of evaluating radiologic findings with clinical outcome, is needed.

The building blocks of a quality day treatment program: the business plan.

This article undertakes two interrelated tasks in order to illustrate the business plan as a dynamic part of the day treatment planning process. To ensure an understanding of basic concepts, it walks the day treatment program planner through the elements of a generic business plan. Building upon this foundation, the paper provides the day treatment program planner with detailed information regarding the various uses to which the material gathered for the business plan may be employed.

The mortality experience of Dow Chemical Louisiana Division employees, 1956-1986.

A major objective of the epidemiology department of the Dow Chemical Company is to report at periodic intervals the cause-specific mortality experience of its employees. This study analyzed the cause-specific mortality experience of 4,229 male and female employees of the Louisiana Division who were employed for at least 1 year from 1956 through 1986. Regardless of the comparison population used to calculate expected numbers (United States, Louisiana, or the surrounding five parish area), fewer deaths were observed for all causes combined as well as for all malignant neoplasms, diseases of the circulatory system, and external causes of death.

Prevalence of back pain and joint problems in a manufacturing company.

To estimate prevalence of back pain and joint problems in employees of a chemical manufacturing company, a questionnaire was administered during medical surveillance examinations between 1987 and 1989. Among 5903 employees completing the questionnaire 35.4% reported back or joint pain during the past year. Back pain lasting 30 days or more occurred in 5.3% of employees, while joint pain and/or swelling occurred in 19.3% of employees. A physician visit was involved for 10.5% and 11.1% of employees reporting back pain and joint problems respectively. A trend of increasing prevalence with increasing age was significant (P less than .001) for all musculoskeletal outcomes. Unadjusted prevalence of back pain and joint problems was significantly higher among men and among whites. After adjusting for age, race, and occupation using logistic regression, the difference in prevalence for the two sexes was diminished or reversed. Similarly, differences in race were diminished when other variables were controlled. Differences in prevalence by occupation were attenuated after adjustment for age, gender, and race. Back pain tended to be reported more frequently for managers, back pain and joint problems for technicians, and back pain requiring physician visit for craftsmen. Self-reported back pain and joint problems during the previous year vary more by age and occupation and less by gender and race in this employed population.

The building blocks of a quality day treatment program: the needs assessment.

This paper is the first in a series of papers which discuss the many necessary ingredients that combine to produce a quality day treatment program. The theme of this article is the assessment of market needs. Included are (1) an introduction to the concepts of needs, (2) a discussion of the movement from need to change in society, (3) an examination of the process of quantifying needs, and (4) a brief description of several different types of needs assessments. The conclusion provides a description of each salient point and indicates its use in day treatment program development.

Lung cancer and hydrogen chloride exposure: results from a nested case-control study of chemical workers.

There are few epidemiologic data available to address the question of potential carcinogenic effects of hydrogen chloride (HCl) exposure on humans. An opportunity arose to augment a nominal HCl exposure classification that had been done earlier for a nested case-control study of lung cancer among a cohort of chemical manufacturing employees. Working from first-hand knowledge of the relevant chemical processes and limited HCl monitoring data, a certified industrial hygienist estimated average exposures for each of the job assignments of 308 lung cancer cases and 616 comparison workers. The risk of lung cancer was then analyzed in relation to several measures of HCl exposure, including duration, a cumulative exposure score, highest average exposure, and latency. None showed evidence of an association between HCl exposure and lung cancer. This is consistent with the limited rodent bioassay data, which also failed to find a tumorigenic response from HCl. Thus, even at high level occupational exposures (up to 3000 micrograms/m3 for several years) there is no evidence that HCl is a human carcinogen.

The positive known association design: a quality assurance method for occupational health surveillance data.

Quality control must be an integral component of an occupational health surveillance program. The positive known association design offers the occupational health physician a method to test, on a population basis (ie, high periodic medical surveillance examination participation rates by the employees), the quality of periodic medical surveillance data. Several well-established biological associations were evaluated and observed in this study, including a dramatic relation between white blood cell counts and smoking. We highly recommend that the positive known association design be incorporated in the quality assurance procedures of occupational health surveillance programs.

A comparison of cause-specific mortality among participants and nonparticipants in a work-site medical surveillance program.

Nonparticipants in general population health surveys have been found to be less healthy than participants, but data on nonparticipants in work-site health surveys have been more scarce. We compared cause-specific mortality among 11,156 male employees of The Dow Chemical Company who participated in at least one work-site health examination between 1967 and 1978 with 6915 employees who did not participate. The nonparticipants experienced higher mortality rates for nearly every cause of death examined but particularly from smoking and alcohol-abuse related diseases. This was especially true during the first 5 years of follow-up, suggesting that some employees do not participate because they are already ill. These findings have important implications for the use of examination data for both primary and secondary disease prevention purposes, and these are discussed.