Biomedical subjects

J W Davis

Publications and source records attributed to J W Davis.

At least 55 records · Page 3Linked to original sources

PubMed1999

Risk factors for falls and for serious injuries on falling among older Japanese women in Hawaii.

OBJECTIVES: To evaluate if similar constellations of factors underlie the risks of falls and injuries on falling for Japanese women as reported for predominately white populations. DESIGN: A prospective cohort study SETTING: The island of Oahu PARTICIPANTS: The older Japanese women who participated in the Hawaii Osteoporosis Study (mean age = 74 +/- 5 (SD) years). MEASUREMENTS: As outcomes: falls and serious injuries on falling. As predictors: anthropometric measurements, measurements of neuromuscular performance, activities of daily living (ADLs), past falls, and other suspected risk factors for falls and serious injuries. RESULTS: In multivariable models, four subject characteristics were positively associated with having a fall (having a fall in the past year (RR = 2.0 (95% CI, 1.5-2.8)), slow chair stands (RR = 1.4 (95% CI, 1.0-1.9), a short height (RR = 1.5 (95% CI, 1.1-2.1)), difficulties with five or more ADLs (RR = 1.5 (95% CI, 1.1-2.1))). Two subject characteristics were negatively associated with having a fall (ability to perform a full tandem balance with eyes closed (RR = .7 (95% CI, .5-1.0)) and having a long functional reach (RR = .7 (95% CI, .5-1.0))). The RRs represent as nearly as possible comparisons of the upper (or lower) quartile and the remaining quartiles. In multivariable models, long times for chair stands (odds ratio (OR) = 3.0 (95% CI, 1.5-6.1)) and a low BMI (OR = 3.1 (95% CI, 1.5-6.4)) were positively associated with having a serious injury among women who had a fall. Among the same women, taking part in an activity they did frequently (OR = .3 (95% CI, .1-.8)) and slow foot reaction times (OR = .3 (95% CI, .1-.8)) were associated negatively with having a serious injury. CONCLUSIONS: The results from this Japanese cohort support the conclusion that women at high risk of falling and serious fall injuries can be identified using a questionnaire and simple, performance-based tests of neuromuscular function. The risk factors for falling overlapped, but were distinct from, those for suffering a serious injury once a fall had occurred.

Accidental Falls↗

PubMed1998

Use of niacin, statins, and resins in patients with combined hyperlipidemia.

Patients in the original Familial Atherosclerosis Treatment Study (FATS) cohort were subgrouped into those with triglyceride levels < or = 120 mg/dL (n = 26) and those with triglyceride levels > or = 190 mg/dL (n = 40). Their therapeutic responses to niacin plus colestipol, lovastatin plus colestipol, colestipol alone, or placebo were determined. Therapeutic response was also determined in the same 2 triglyceride subgroups (n = 12 and n = 27, respectively) of patients selected for low levels of high-density lipoprotein (HDL) cholesterol and coronary artery disease. These triglyceride criteria were chosen to identify patient subgroups with high likelihood of "pattern A" (normal-size low-density lipoprotein [LDL] particles and triglyceride < or = 120 mg/dL) or "pattern B" (small dense LDL and triglyceride > or = 190 mg/dL). Our findings in these small patient subgroups are consistent with the emerging understanding that coronary artery disease patients presenting with high triglyceride levels have lower HDL-C, smaller less buoyant LDL-C, and greater very low-density lipoprotein (VLDL) cholesterol and VLDL apolipoprotein B, and are more responsive to therapy as assessed by an increase in HDL-C and reduction in triglycerides, VLDL-C, and VLDL apolipoprotein B. In the FATS high-triglyceride subgroup with these characteristics, a tendency toward greater therapeutic improvement in coronary stenosis severity was observed among those treated with either of the 2 forms of intensive cholesterol-lowering therapy. This improvement is associated with therapeutic reduction of LDL-C and elevation of HDL-C, but also appears to be associated with drug-induced improvement in LDL buoyancy.

Anticholesteremic Agents↗

PubMed1998

Comparison of dose-response relationships for induction of lipid metabolizing and growth regulatory genes by peroxisome proliferators in rat liver.

The regulation of gene expression via the peroxisome proliferator-activated receptor (PPAR) is believed to be critical in the effects of peroxisome proliferators on lipid metabolism and possibly in hepatocarcinogenesis. The involvement of PPAR in the peroxisome proliferator-mediated induction of fatty acid metabolizing genes such as acyl-CoA oxidase (ACO), fatty acid-binding protein (FABP), and cytochrome P450IVA1 (CYP4A1) has been clearly demonstrated. However, the induction by peroxisome proliferators of important growth regulatory genes such as c-myc has not been investigated extensively. In these studies we examined the dose-response relationships for the induction of mRNA for the PPAR-regulated and lipid metabolizing genes ACO, FABP, and CYP4A1 and compared them to the immediate early gene c-myc. Liver mRNA from rats fed various amounts of the peroxisome proliferator Wy14,643 for 13 weeks was utilized. The lipid metabolism and growth regulatory genes were induced by subchronic administration of Wy14,643 but to varying degrees and with different sensitivities. The lowest dose that resulted in a significant change in ACO and FABP expression was 10 ppm. The mRNA for CYP4A1 and c-myc was significantly affected at the lowest dose examined (5 ppm). Also, the maximal induction ranged from 10(5)-fold (CYP4A1) to less than 10-fold (FABP) relative to vehicle-treated animals. The accumulation of mRNA for ACO, FABP, and CYP4A1, but not c-myc, showed typical receptor-mediated dose-response relationships. The effects on gene expression were compared to rates of hepatic cell proliferation, a pertinent marker of tumor promotion and hepatocarcinogenesis. Surprisingly, ACO mRNA showed an excellent correlation (r2 = 0.9) while c-myc mRNA exhibited a poor correlation (r2 = 0.3) with cell proliferation in rat liver. Although the differences between the dose-response relationships of ACO and c-myc mRNA accumulation may suggest immediate early genes are not controlled by PPAR, evidence from PPARalpha null mice support this receptor in both lipid metabolism and growth regulatory genes. This study shows the complexity of responses mediated by peroxisome proliferators, with ACO being a good marker of PPAR-mediated events as well as cell proliferation, while c-myc, a known growth regulatory gene, was induced by Wy14,643 partially via PPAR but did not correlate well with cell proliferation.

Acyl-CoA Oxidase↗

PubMed1998

Can Ringer's lactate be used safely with blood transfusions?

BACKGROUND: Blood bank recommendations specify that Ringer's lactate solution (LR) should be avoided while transfusing blood. However, there are few studies either evaluating or quantifying increased coagulation during rapid infusion of LR and blood. DESIGN AND METHODS: Whole blood (WB, n = 25) and packed red blood cells (PRBC, n = 26) were rapidly admixed with normal saline (NS), Lactate solution and LR with 1 g (LR-1), 2 g (LR-2), and 5 g (LR-5) CaCl2/L solutions for assessment of infusion time, filter weight, and clot formation. RESULTS: No significant differences in infusion time or filter weight using WB or PRBC with NS or LR were seen. No significant difference in clot formation between NS and LR with WB or PRBC was found, but the presence of visible clot was increased in the LR-5 group (P = 0.013, WB, and P = 0.002, PRBC). CONCLUSION: A comparison of LR and NS with rapid infusion rates of blood showed no significant difference between infusion time, filter weight and clot formation. Blood bank guidelines should be revised to allow the use of LR in the rapid transfusion of PRBC.

Blood Coagulation↗

PubMed1998

Base deficit is superior to pH in evaluating clearance of acidosis after traumatic shock.

OBJECTIVE: This study was done to evaluate the differences in base deficit (BD) clearance, pH normalization, and the occurrence of complications between survivors and nonsurvivors after trauma. DESIGN: Concurrent data entry with retrospective review. METHODS: Trauma patients meeting registry criteria from July 1990 through August 1995 with arterial blood gases performed within 1 hour of admission and admission BD < or = -6 were included. Data was grouped by BD category (moderate, -6 to -9; severe, < or = -10). Group means +/- SEM were compared with a two-tailed t test. MEASUREMENTS AND MAIN RESULTS: Six hundred seventy-four patients met entry criteria. Survivors in both the moderate and severe BD groups had improved their BD within 4 hours and normalized their BD by 16 hours. Nonsurvivors did not improve their BD category until 8 hours (for the severe group) and 16 hours (for the moderate group) and did not normalize BD before 24 hours. The BD differences between survivors and nonsurvivors were significant at each time interval, whereas pH differences were significant at 2 hours in the moderate group and at 2, 16, and 24 hours in the severe group. Patients who failed to improve their BD > -6 had an increased frequency of adult respiratory distress syndrome, multiple organ failure, and mortality. CONCLUSION: Base deficit reveals differences in metabolic acidosis between survivors and nonsurvivors not shown by pH determinations and is clearly a better marker of acidosis clearance after shock.

Acidosis↗

PubMed1998

Patients with gunshot wounds to the head do not require cervical spine immobilization and evaluation.

OBJECTIVE: The purpose of this study was to determine the incidence of indirect spinal column injury in patients sustaining gunshot wounds to the head. METHODS: A retrospective review of patient records and autopsy reports was conducted of patients admitted with gunshot wounds to the head between July of 1990 and September of 1995 were included. Those with gunshot wounds to the neck and those who were dead on arrival were excluded. RESULTS: A total of 215 patients were included in the study. Cervical spine clearance in 202 patients (93%) was determined either clinically, radiographically, or by review of postmortem results. No patients sustained indirect (blast or fall-related) spinal column injury. Three patients had direct spinal injury from bullet passage that were apparent from bullet trajectory. More intubation attempts occurred in patients with cervical spine immobilization (49 attempts in 34 patients with immobilization versus five attempts in four patients without cervical spine immobilization, p = 0.008). CONCLUSIONS: Indirect spinal injury does not occur in patients with gunshot wounds to the head. Airway management was compromised by cervical spine immobilization. Protocols mandating cervical spine immobilization after a gunshot wound to the head are unnecessary and may complicate airway management.

Adult↗

PubMed1998

Base deficit in the elderly: a marker of severe injury and death.

BACKGROUND: Base deficit has been used as a marker of significant injury and to predict resource utilization and mortality. The significance of base deficit in trauma patients 55 years and older has not been specifically evaluated. The purpose of this study was to determine the utility of base deficit in assessing older trauma patients versus a younger cohort. METHODS: Data were obtained from the trauma registry on trauma patients admitted to a Level I trauma center. Arterial blood gases were obtained within 1 hour of arrival, by protocol, in 2,631 patients, and of these, 274 patients were 55 years or older. Data are presented as means+/-SEM. Statistical analysis was done by paired t test, analysis of variance, and chi2 analysis. Significance was attributed to a p value < 0.05. RESULTS: Patients older than 55 years were significantly more likely to have sustained blunt trauma (86 vs. 69%; p < 0.001). Despite similar Injury Severity Scores and base deficit values, older patients had markedly greater mortality and intensive care unit lengths of stay. A base deficit of < or = -6 had positive predictive values for Injury Severity Scores > or = 16 for 76% of patients younger than 55 years and 78 % of patients 55 years and older. The negative predictive value of a normal base deficit for Injury Severity Scores < or = 16 was 60% for the younger cohort and only 40% for patients 55 years and older (p < 0.001; chi2). CONCLUSIONS: A base deficit of < or = -6 is a marker of severe injury and significant mortality in all trauma patients, but it is particularly ominous in patients 55 years and older. Patients older than 55 years may have significant injuries and mortality risk without manifesting a base deficit out of the normal range.

Acidosis↗

PubMed1998

Strength, physical activity, and body mass index: relationship to performance-based measures and activities of daily living among older Japanese women in Hawaii.

OBJECTIVES: Remaining strong, lean, and physically active may contribute to successful aging, both by maintaining function and by enabling more independent living. The study objective was to investigate this hypothesis among a long-lived population of older Japanese women. DESIGN: A cross-sectional study. SETTING: The island of Oahu, Hawaii. PARTICIPANTS: A total of 705 community-dwelling women (mean age, 74; range, 55-93). MEASUREMENTS: As outcomes, 7 physical performance measures including walking speed, the Get Up and Go test, chair stands, functional reach, and hand and foot reaction times, and 8 questions regarding activities of daily living (ADL). As possible predictors, physical activity, body mass index, and quadriceps, grip, and triceps strength. RESULTS: In multivariable models, one or more of the strength tests was associated positively with six of the seven performance-based measures. Among the significant associations, 1-SD increases in strength were associated with 2 to 4% increases in performance compared with the sample mean. Physical activity was independently, and positively associated with the most complex of the tests, the Get Up and Go test. Body mass index (BMI), in contrast to strength and physical activity, was negatively associated with five of the seven performance tests. Among the significant associations, 1-SD increases in BMI were associated with 3 to 8% reductions in performance. In multivariable models strength was also associated positively with seven of the eight ADLs. In the same models, physical activity was positively associated with five and BMI was negatively associated with six of the ADLs. CONCLUSION: The results suggest that remaining strong, lean, and physically active provided wide-ranging benefits for this population of older Japanese women.

Activities of Daily Living↗

PubMed1998

Development and validation of a geriatrics attitudes scale for primary care residents.

OBJECTIVE: To develop and validate an instrument measuring attitudes toward older persons and caring for older patients. DESIGN: Cross-sectional and longitudinal studies. SETTING: An academic medical center. PARTICIPANTS: Initial Study: 121 primary care residents (n = 96), fellows (n = 14), and faculty (n = 11) participated in instrument development in 1995. Longitudinal Study: 95 residents (n = 87) and fellows (n = 8) of the initial cohort participated in the 1996 follow-up study, and 61 of the initial cohort (57 residents and 4 fellows) participated in the 1997 follow-up study. Cross Validation Study: 96 first-year residents (n = 78) and fellows (n = 18) participated in this study. MEASUREMENTS: A 14-item geriatrics attitudes scale was developed. The items were selected from a pool of 37 items administered to the 121 participants in the initial study. RESULTS: The instrument demonstrated high reliability (Cronbach's alpha = .76) and known-groups and construct validity. Attitudes were progressively more positive with more medical training (P < .001), and residents with greater career interest in geriatrics scored higher than those less interested (P = .007). Cross validation results supported the reliability and validity of the instrument. Longitudinal data showed significantly different trends of attitude changes among groups of residents and fellows over a 2-year period. CONCLUSIONS: The 14-item geriatrics attitudes scale developed in this study shows sound reliability, validity, and sensitivity to change among primary care residents. The performance of other groups of medical trainees and the relationship of attitude changes to specific medical training warrant further investigation.

Aged↗

PubMed1998

The effects of ventricular pacing on left ventricular geometry, function, myocardial oxygen consumption, and efficiency of contraction in conscious dogs.

The effects of ventricular pacing on left ventricular (LV) dynamic geometry, function, and myocardial oxygen consumption (MVO2) were measured in 12 conscious dogs using sonomicrometry, micromanometry, ultrasonic flow probes, and oximetry catheters during right atrial (A-) and right ventricular (V-) pacing at 150 beats/min. Systolic function was quantified using slopes (MW) and volume-intercepts (VW) of linear relationships between end-diastolic volume (EDV) and stroke work (SW) for data obtained during vena caval occlusion. V-pacing shifted SW-EDV relationships downward (MW decreased from 97 +/- 21 to 81 +/- 21 Kerg/mL) and to the right (VW increased from 14 +/- 11 to 20 +/- 12 mL) in comparison with A-pacing (P < 0.02). These functional changes correlated with altered contractile geometry manifest as early shortening in the septal free wall relative to anterior-posterior dimension (increased minor axis mid-wall eccentricity at end-diastole and begin-ejection). Steady-state LV power output decreased from 802 +/- 213 mW during A-pacing to 514 +/- 170 mW during V-pacing (P < 0.05), while MVO2 remained relatively unchanged during V-pacing (10 +/- 3 mL O2/min vs 11 +/- 3 mL O2/min during A-pacing, P = NS). As a result, overall LV efficiency decreased from 0.24 +/- 0.08 during A-pacing to 0.16 +/- 0.06 during V-pacing (P < 0.05). These data illustrate the impact of V-pacing on dynamic LV geometry and function, including impaired LV work output at all physiological levels of preload. Most importantly, the relationship between LV work output and MVO2 is depressed during V-pacing, emphasizing the interaction between LV mechanics and pump efficiency in intact subjects. As a result, measures taken to restore normal contractile geometry might improve LV efficiency and performance when V-pacing is necessary.

Animals↗

PubMed1998

Falls among community-dwelling elderly in Japan.

Japanese have a lower incidence of hip fracture than Caucasians despite having lower bone mass. Hip fractures usually occur after a fall, and differing incidence rates of falls might explain the observed differences in hip fracture rates. To explore this hypothesis, we studied falls and related conditions among 1534 (624 men, 910 women) community-dwelling people aged 65 years and over in Japan and compared the prevalence of falls to Japanese-Americans living in Hawaii and to published studies of Caucasians. In Japan, 9% of the men and 19% of the women reported one or more falls during the past year. The prevalence of falls increased with age in both genders and was greater among women compared with men. In logistic regression models, having musculoskeletal disease, physical disability or limited activity increased the risk of falls by two to four times in both genders. Most fallers (92%) reported fear of future falls, and about one third of fallers reported that they went out less often as a result of their falls. Compared with native Japanese, the age-standardized prevalence of falls among Japanese-Americans was similar but about twice as high for Caucasians, which may explain the lower hip fracture risk of Japanese.

Accidental Falls↗

PubMed1998

Fatal alcohol-related traffic crashes increase subsequent to changes to and from daylight savings time.

On the hypothesis that sleepiness and alcohol interact to increase the risk of alcohol-related traffic fatalities, the percentages of alcohol-related fatal traffic crashes were assessed for the entire state of New Mexico for the years 1989-1992, for each of the seven days that preceded the changes to and from Daylight Savings Time and for each of the 14 days which followed the changes to and from Daylight Savings Time. Consistent with our hypothesis the percentage of alcohol-related fatal crashes increased significantly during the first seven days after these changes in Daylight Savings Time.

Accidents, Traffic↗

PubMed1998

A comprehensive approach to clinical evaluation.

Historically, the summative clinical evaluation of nursing students has been problematic. Tools of measurement for clinical performance have been subjective and, at times, biased at several levels. With these thoughts and past experiences in mind, the faculty in an associate degree nursing program developed a comprehensive approach to summative clinical evaluation. The process began with the development and implementation of a Clinical Performance Manual (CPM) describing five components of the summative evaluation process. These included the: ability to consistently exhibit professional behaviors; random skills performance examination; plan of care examination; critical situations examination; and required course assignments. These components were developed with the intent of objectifying the measurement of cognitive, affective, and psychomotor skills of students. After 1 year of implementing this process with 250 students, feedback received from faculty and students was reviewed and discussed. Reliability and validity studies have been conducted. A decision was made to continue with this new method of evaluation. Recommendations include piloting and implementing the process in others schools and programs.

Clinical Competence↗

PubMed1998

Does free fluid on abdominal computed tomographic scan after blunt trauma require laparotomy?

BACKGROUND: Abdominal computed tomographic (CT) scans are used in the evaluation of blunt trauma. The purpose of this study was to determine if isolated intraperitoneal fluid seen on CT scan necessitates laparotomy. METHODS: Trauma registry records of patients who underwent abdominal computed tomography from January 1994 through January 1997 were studied. Data were reviewed for age, gender, CT scan interpretation, associated injuries, and operative findings. RESULTS: Abdominal injury was identified in 126 patients. Seventy-eight patients had evidence of solid-organ injury and 17 patients had extraperitoneal injury. Isolated intraperitoneal fluid was identified in 31 patients. All patients with isolated fluid underwent laparotomy; 29 of these procedures (94%) were therapeutic. Bowel injuries occurred in 18 patients and mesenteric injuries in 8 patients. Five patients had intraperitoneal bladder rupture, and undetected solid-organ injuries were found in two patients. Other organs injured included the stomach, pancreas, ovary, and uterus. CONCLUSION: Exploratory laparotomy was therapeutic in 94% of patients. Isolated intraperitoneal fluid on CT scan after blunt trauma mandates laparotomy.

Abdominal Injuries↗

PubMed1997

Trauma deaths in a mature urban vs rural trauma system. A comparison.

OBJECTIVE: To compare the timing, severity, and injury characteristics of patients dying from trauma in an urban vs a rural setting. DESIGN: Retrospective review of autopsy database (urban) and medical examiner database (rural), with selected medical chart review. SETTING: An organized urban trauma system with 6 trauma centers and a rural state with no formal trauma system and 1 trauma center. PATIENTS: All trauma fatalities occurring in an urban (n = 612) and a rural (n = 143) setting during a 1-year period. RESULTS: In the urban system, 248 patients (40.5%) died at the scene of injury compared with 103 (72%) patients in a rural environment. During the first 24 hours of hospitalization 243 (39.7%) urban patients died compared with 23 (16%) rural patients. Eighty-nine urban patients (14.5%) and 17 rural patients (11.8%) survived for more than 24 hours but later died in the hospital. The mean age of those who died was significantly greater in the rural trauma system than in the urban trauma system (P < .001), and the Injury Severity Score was significantly less in the rural trauma system than in the urban trauma system (P < .01). In the patients who died after being admitted to the hospital for more than 24 hours there was a significantly higher rate of preexisting comorbidity in the rural patients than in the urban patients (P < .05). The most frequent cause of death in the rural setting was multisystem organ failure; head injury was the most common cause of death in the urban setting. CONCLUSIONS: Patients who die in a rural area without a formal trauma system are more likely to die at the scene, are less severely injured, and are older. Rural trauma patients who are admitted to a hospital and who survived for at least 24 hours before dying are older, less severely injured, have significantly more comorbidities, and are more likely to die of multisystem organ dysfunction than their urban counterparts. These differences reflect the different patient populations and injury patterns that confront urban and rural trauma centers. The higher proportion of scene deaths in the rural environment may reflect the longer discovery and transport times that occur in a rural setting.

Adolescent↗

PubMed1997

Spinal cord injury. A preventable public burden.

BACKGROUND: Spinal cord injury (SCI) is a devastating occurrence with important consequences for the individual and society. Previous studies have documented the epidemiology and costs of SCI and the rehabilitation needs after SCI; however, data about the preventability of SCI are lacking. OBJECTIVE: To test the hypotheses that most SCIs are preventable and that much of the cost of SCI is borne by the public. DESIGN: Retrospective review of medical records and trauma registry data. SETTING: A 417-bed county hospital with a level I trauma center. METHODS: To evaluate the preventability of SCI, the records of trauma patients sustaining SCI from July 1, 1990, through June 30, 1995, were reviewed. The criteria for preventability of blunt injuries included the following: failure to use restraint devices; intoxication of drivers, motorcyclists, or pedestrians; and falls or diving accidents involving the use of drugs or alcohol. The criteria for preventability of penetrating injuries included the following: illegal possession of a firearm, accidental discharge of a weapon, and suicide attempts. Statistics were performed with the paired Student t test and chi 2 with significance attributed to a P value less than .05. RESULTS: Spinal cord injury occurred in 150 patients; 71% of the injuries were the result of blunt trauma. Injury was potentially preventable in 74% of the blunt injuries and 66% of the penetrating injuries (P = .15). Patients with a penetrating SCI were younger (P < .001) and relied more on public funding than did those with a blunt SCI (65% vs 81%; P = .05). CONCLUSIONS: Most SCIs are preventable with strict enforcement of existing statutes. Furthermore, the financial burden of these preventable injuries is largely borne by the public.

Critical Care↗

PubMed1997

More guns and younger assailants. A combined police and trauma center study.

OBJECTIVE: To test the hypothesis that guns have become the weapon of choice for assaults and that both assailants and victims have become progressively younger. DESIGN: Retrospective review of trauma center and police department data sources. SETTING: Regional trauma center with university affiliation; municipal police department. SUBJECTS: Victims of assault with a deadly weapon from 3 discontiguous years. MAIN OUTCOME MEASURES: Age of assailant and victim, type of injury, frequency of blunt vs penetrating injury. RESULTS: From June 1991 to May 1992 and June 1993 to May 1994, the incidence of penetrating trauma increased from 27% to 35% of trauma center admissions (chi 2 test; P < .001). During the period from June 1985 to May 1994, assault with a deadly weapon increased by 220% and firearms became the most common assault mechanism (from 32% to 54%; chi 2 test; P < .001). Assailants using guns became significantly younger, with the percentage of assailants aged 11 to 20 years increasing from 24% to 47% (chi 2 test; P = .001). The ages of assault victims also decreased (P < .003), but were more evenly distributed across age categories. CONCLUSIONS: The incidence of penetrating trauma has increased in both absolute numbers and in relative proportion to blunt trauma. Firearms have become the weapon of choice and the single largest group of assailants are 11 to 20 years of age. The use of concurrent police and trauma center databases provides a more cogent basis for developing effective violence prevention strategies.

Adolescent↗

PubMed1997

Environmental assessment of the alkanolamines.

This review provides a summary of current information available on the environmental fate and aquatic toxicology of the alkanolamines. Because these materials are widely used, there is a need to understand their fate and effects in the environment. This assessment was confined to information regarding selected physical properties of the alkanolamines as well as their potential for degradation in the atmosphere, soil, surface water, and groundwater. In addition, their relevant aquatic toxicological information and bioconcentration potential were evaluated. In general, the alkanolamines have high water solubilities and low to moderate vapor pressures. Some are solids whereas others are liquids at room temperature. Aqueous solutions of the alkanolamines are basic, with the pKas decreasing with increased alkyl substitution. Predictions of the environmental distribution of these compounds, based on a unit world model of Mackay and Paterson, suggested that alkanolamines would partition primarily into the aqueous compartment at equilibrium, with the remainder distributed to the atmosphere. Only a very small fraction of these materials is expected to sorb to soil or sediments. However, adsorption mechanisms other than partitioning into the soil organic layer were not considered in this model. Since polar compounds may sorb to soil by alternate mechanisms, this model may underestimate the true adsorption potential and subsequent environmental distribution of the alkanolamines. Future work with these compounds should focus on other types of adsorption mechanisms that could impact the environmental distribution of the alkanolamines. Although only small amount of the alkanolamines are expected to partition to the atmosphere, they are expected to be removed by reactions with photochemically generated hydroxyl radicals. They may also be removed from the atmosphere by precipitation, due to their high water solubility. Because of the relatively low levels expected to be present in the atmosphere and the relatively short half-lives, the alkanolamines are not expected to adversely impact air quality. Alkanolamines have also been shown to be highly susceptible to biodegradation and are not expected to persist in the environment. Results from numerous studies have shown that these materials undergo rapid biodegradation in soil, surface waters, and wastewater treatment plants. Degradation rates for these compounds may vary, with half-lives routinely in the range of 1 d to 2 wk, depending on the length of acclimation period and other environmental factors. The relatively low bioconcentration factor (BCF) values reported for the alkanolamines indicate that they would not be expected to bioconcentrate in aquatic organisms. Available data on the toxicity of the alkanolamines to aquatic organisms suggest low toxicity to the majority of the species studied. Based on the facts that alkanolamines exhibit low aquatic toxicity, are shown to biodegrade in a wide range of environments, and exhibit no tendency to bioaccumulate, the routine manufacturing, use, and disposal of these materials are not expected to adversely impact the environment. With increased emphasis by consumers and regulatory agencies for industry to develop products that are "environmentally friendly," these properties of the alkanolamines make them an attractive choice for a wide range of applications.

Amino Alcohols↗