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Biomedical subjects

K H Kilburn

Publications and source records attributed to K H Kilburn.

At least 19 recordsLinked to original sources
PubMed2000

Indoor air effects after building renovation and in manufactured homes.

PROBLEM: The objective was to measure and compare the neurobehavioral and respiratory effects of exposures to indoor air in people living in manufactured homes and occupying buildings during renovation and compare them with effects on subjects exposed to formaldehyde at work. METHODS: Ten people living in manufactured homes and 10 people exposed to chemicals during renovation of their offices or homes had measurements made of balance, visual fields, reaction time, hearing, grip strength, and vibration sense. Psychological measurements included cognition, recall, perceptual motor speed, long-term memory, and mood states. RESULTS: Exposures to indoor air were associated with abnormal simple and choice reaction time, abnormal balance with the eyes open and with the eyes closed, abnormalities of color confusion index, scotoma in visual fields, reduced verbal recall, digit symbol score, and elevated abnormal moods. The effects on the two groups of 10 were similar and resembled those from formaldehyde exposure but with less cognitive impairment. CONCLUSIONS: Adverse effects from indoor air in manufactured homes and during renovations were less severe but similar to those from occupational formaldehyde exposures. This suggests that formaldehyde has a major role in health problems from indoor air.

Adult↗
PubMed2000

Visual and neurobehavioral impairment associated with polychlorinated biphenyls.

To determine whether residents exposed to PCBs and thermolysis products had impaired neurobehavioral functions, the performance of 98 exposed adults was compared with 58 unexposed regional referents (all volunteers). Visual field performance, color confusion index, balance as sway speed, blink reflex latency R-1, hearing, grip strength, simple and choice visual reaction times problem solving for Culture Fair and digit symbol, recall memory, peg placement, trail making A and B for attention and dexterity and long-term memory were tested. A profile of mood states (POMS) and questionnaires for chemical exposures, medical histories and the frequency of 35 symptoms were completed. Only statistically significant differences are described. Exposed subjects had slower simple and choice reaction times and faster sway speeds with eyes closed and open. Color discrimination and visual performance scores were lower and visual fields were often constricted. Scores on Culture Fair, digit symbol, vocabulary and verbal recall were lower. Placement of pegs in a slotted pegboard was slower and trail making A and B took longer. Even embedded memory test scores including vocabulary were lower. POMS scores were elevated. There were no competing chemical exposures, confounding factors or other explanations for the findings. Long residential exposure to PCBs was associated with visual defects and impaired neurophysiologic and neuropsychologic functions.

Adult↗
PubMed1999

Neurobehavioral and respiratory findings in jet engine repair workers: A comparison of exposed and unexposed volunteers.

Workers repairing jet engines had respiratory, rheumatic, and neurobehavioral symptoms. They had welded and ground stainless steel parts using hard metal tools and cleaned metal with chlorinated and fluorinated organic solvents. We compared 154 workers and 112 unexposed subjects, all volunteers of similar ages and with similar educational levels, for abnormalities on chest radiographs, spirometric measurements, and questionnaires. Also appraised were performance of reaction time, balance, blink reflex latency, color discrimination, Culture Fair, vocabulary, slotted pegboard, trail making A and B, profile of mood states (POMS), and frequencies of 35 symptoms. Compared to unexposed subjects, workers had significantly more respiratory symptoms but no differences in pulmonary function. They had significantly prolonged simple and choice reaction time (P<0.0001), and abnormal balance with eyes open and eyes closed (P<0. 0001), and abnormal color discrimination. Blink reflex latency was abnormal in both exposed workers and in local unexposed compared to other reference groups. Focus of the inquiry on lung disease helped ensure that for neurobehavioral tests confounding factors were minimal and known biases were small. We tentatively attribute the neurobehavioral impairments and increased symptom frequencies to chlorinated solvent exposure. Excessive respiratory symptoms are attributed to welding stainless steel combined with cigarette smoking. Specifically, manganese exposure may have affected the respiratory and the central nervous systems.

Adult↗
PubMed1999

Neurotoxicity from airborne chemicals around a superfund site.

A pilot investigation had shown that 88 people living within 2.4 km of a waste chemical disposal and oil-reprocessing facility which operated from 1966 to 1983 had reduced neurobehavioral performance compared to 66 regional referents. A geographic model of dispersal predicted less effect with greater distance from the distilling. To explore this gradient and the boundaries of the adverse effects, we tested 408 residents in random proportional samples of concentric zones from the center out to 4.8 km that were divided by compass octants. Reaction times, balance, blink reflex latency, color discrimination, Culture Fair, pegboard, and Trail Making A and B were measured. Patients completed a Profile of Mood States, frequency of 33 symptoms, and medical, occupational, and exposure histories. Distance and direction from the site and duration of residence were examined for effect on each test score by stepwise linear regression. Exposed subjects' had diminished reaction time, balance, color score, and scores for Culture Fair, pegboard, and Trail Making A and B compared to referents. Functional impairment was not correlated with distance or direction from the site but subjects with short durations of residence had better function on one test. Combinations of these factors were not predictive.

Adult↗
PubMed1997

Chlordane as a neurotoxin in humans.

To assay and profile chronic neurobehavioral impairment associated with chlordane exposure in symptomatic patients, consecutive evaluations of nine patients were done with sensitive neurophysiologic and neuropsychologic tests for neurobehavioral function. Their visual fields, balance, reaction time, blink, color discrimination, grip strength, cognitive function, recall, memory, and perceptual motor speed were tested, and mood states and frequencies of 35 symptoms were appraised. Prevalences of abnormality were compared test-by-test to predict values with confidence intervals, and mean values for the group were compared with reference values. Testing showed abnormal balance with eyes closed in 7, abnormal color discrimination in 6, verbal recall deficit in 5, and prolonged blink reflex latency, prolonged choice reaction time, and decreased Culture Fair scores in 4 each. Profile of Mood States score was elevated in 5. These observations suggest that chlordane causes protracted neurotoxicity.

Adult↗
PubMed1997

Exposure to reduced sulfur gases impairs neurobehavioral function.

BACKGROUND: In the 19th century, deaths from acute exposure to hydrogen sulfide (H2S) portended permanent brain injury from nonlethal doses. The neurobehavioral effects of H2S exposures lasting from moments to years were compared in 16 subjects, 2 years to 22 years afterward. METHODS: Neurophysiologic and psychologic tests were used to appraise mood status and frequencies of 35 symptoms. Functions and frequencies, described as percent predicted adjusted for age, sex, educational achievement, and other factors, were compared with those in an unexposed population. RESULTS: Frequencies were elevated for 31 of 33 symptoms. Balance was impaired (246% predicted with eyes closed, 159% predicted with eyes open), and simple and choice reaction times were prolonged (151% and 130% predicted, respectively). Visual fields performance was decreased to 72% predicted (right) and 55% predicted (left), color discrimination was abnormal, and hearing was decreased. Psychologic domains showed cognitive disability, reduced perceptual motor speed, impaired verbal recall and remote memory, and abnormal mood status. CONCLUSIONS: Exposure to H2S must be avoided.

Adult↗
PubMed1996

Persistent neurotoxicity from a battery fire: is cadmium the culprit?

Two train conductors had chest tightness, painful breathing, muscle cramps, and nausea after fighting a fire in a battery box under a passenger coach. Shortly thereafter, they became anosmic and had excessive fatigue, persistent headaches, sleep disturbances, irritability, unstable moods, and hypertension. Urinary cadmium and nickel levels were elevated. Neurobehavioral testing showed, in comparison to referents, prolonged reaction times, abnormal balance, prolonged blink reflex latency, severely constricted visual fields, and decreased vibration sense. Test scores showed that immediate verbal and visual recall were normal but delayed recall was reduced. Scores on overlearned information were normal. Tests measuring dexterity, coordination, decision making, and peripheral sensation and discrimination revealed abnormalities. Repeat testing 6 and 12 months after exposure showed persistent abnormalities. Cadmium and vinyl chloride are the most plausible causes of the neurotoxicity, but fumes from the fire may have contained other neurotoxic chemicals.

Accidents, Occupational↗
PubMed1996

Effects of a hydrochloric acid spill on neurobehavioral and pulmonary function.

A container truck leaked 800 L (200 gallons) of hydrochloric acid (HCl) near a mobile home park in Louisiana in August 1993. The investigating officer and residents became acutely ill with burning and tearing eyes, burning throats, headache, chest pain, shortness of breath, and flu-like complaints. Twenty months later, 45 exposed adult subjects and 56 age-matched referents underwent neurobehavioral testing, including balance, reaction time, blink-reflex latency, and spirometry. They also completed health questionnaires and a profile of mood states. The exposed subjects differed significantly from referents by t test and by covariance analysis for balance, simple and two-choice visual reaction time, digit symbol, and for placing pegs in a pegboard. Proximity to the HCl spill increased sway speeds and impaired pulmonary midflow rates. Chronic neurobehavioral dysfunction and airways obstruction were found after environmental HCl exposure.

Accidents, Traffic↗
PubMed1995

Prediction equations for balance measured as sway speed by head tracking with eyes open and closed.

OBJECTIVES: To provide prediction equations for balance measured as sway speed, a population of randomly selected subjects was used as a model. METHODS: 265 subjects were selected from voter registration rolls in Arizona and Louisiana, USA. For validation these predicted values were compared with observed values obtained from a second population in California, USA. RESULTS: Sway speed with eyes open as a natural logarithm was: 1n (open) = -0.248333 -0.009634 x age +0.000164 x age2 and sway speed with eyes closed was: 1n (closed) = -0.585707 -0.023074 x age +0.000315 x age2 + 0.038496 x height (cm) CONCLUSIONS: The natural logarithm of balance with the eyes open was related to age by both linear and quadratic functions. Additionally with the eyes closed balance was dependent on height. These equations can be used to predict performance of groups being studied for effects of noise and chemicals. To define abnormality of individual subjects the predicted value plus 1.5 SDs could be used.

Adolescent↗
PubMed1995

Do radiographic criteria for emphysema predict physiologic impairment?

OBJECTIVE: The functional consequences of pulmonary emphysema have been estimated from autopsy studies. This antemortem study correlates structure as assessed by criteria applied to chest radiographs and function in earlier disease. SUBJECTS AND METHODS: Four thousand one hundred seven male shipyard and construction workers had chest radiographs scored for asbestosis using International Labour Office criteria and for emphysema using five criteria: hyperlucent lung fields, low flat diaphragms on posteroanterior views, low flat diaphragms on lateral radiographs, a wide retrosternal space, and bullae. Total lung capacity (TLC) was measured by planimetry of radiographs and forced vital capacity (FVC) and flows by spirometry: TLC minus FVC equaled residual volume (RV). All were expressed as percentage of predicted (% pred) adjusted for height, age, and duration of cigarette smoking. Linear regression modeling examined the influence of each emphysema criterion on function measurements. RESULTS: Four hundred three (10.1%) of 4,107 men had two or more emphysema criteria and 24.5% had asbestosis. Prevalence of 2 criteria varied by smoking status and was present in 20% of current smokers, 7.5% of ex-smokers, and 2% of never smokers. The TLC % pred and RV/TLC increased and % pred of FEV1/FVC and FEF25-75, FEV1, and FVC decreased with increasing radiographic emphysema criteria. Forty-four (10%) had normal results of spirometry with two or more radiographic emphysema criteria. CONCLUSION: Impairment of airway function worsened with each additional radiographic criteria of emphysema. These criteria were more strongly associated with an increase in RV/TLC than an increase in TLC.

Asbestosis↗
PubMed1994

Balance measured by head (and trunk) tracking and a force platform in chemically (PCB and TCE) exposed and referent subjects.

To determine comparability of methods, postural sway was measured simultaneously with a force platform and a device that registers head (and trunk) movements (head tracking). The effects of age, sex, height, weight, shoe area, and grip strength on both measurements were examined in 162 subjects. To determine whether either method had advantages in detecting abnormal balance 46 reference subjects were compared with 116 people randomly selected from 500 residents whose well water was contaminated with polychlorinated biphenyls (PCBs) and trichloroethylene (TCE) from a metal casting plant. Speed, mean radius, and distance of sway were equally reproducible with both methods. Correlation coefficients were 0.672 with the eyes closed and 0.588 with the eyes open. The balance of those exposed to PCBs and TCE was significantly worse than that of unexposed subjects by both head tracking (1.50 + 71 cm/s v 1.27 + 0.36 cm/s; p < 0.034) and the force platform (4.93 + 1.56 N (kg force) v 4.29 + 1.14 N; p < 0.013) with the eyes closed and differences were also significant with the eyes open. Head tracking and the force platform produced equivalent results. Measurement by head tracking is recommended for field studies because the device is more portable and is less influenced by weight and height. Both methods showed impaired balance associated with years of exposure to PCBs and TCE.

Adult↗
PubMed1994

Airways obstruction from asbestos exposure. Effects of asbestosis and smoking.

OBJECTIVE: To define the apparent steps in developing airways obstruction vs restrictive lung disease in men exposed to asbestos for more than 20 years who had never smoked vs cigarette smokers. DESIGN: Physiologic signs of asbestosis were studied in cross-sectional age-matched groups of never, current, and ex-cigarette smoking workers. SETTING AND PARTICIPANTS: The study included 8,720 asbestos-exposed construction and shipyard workers in the United States. MEASUREMENTS: FVC, FEV1, FEF25-75, and FEF75-85 were measured by spirometry and total lung capacity (TLC) by planimetry of standard chest radiographs and adjusted for height, age, and duration of cigarette smoking and expressed as percentage of predicted. TLC minus FVC yielded RV. We compared means and mean residuals (measurement minus group mean) expiratory flows and lung volumes in 1,146 men with pulmonary asbestosis age matched to 1,146 without asbestosis who had similar durations of asbestos exposure and to 370 men without asbestos exposure. Next, flows and volumes were regressed against the International Labour Office (ILO) profusion scale of irregular opacities on chest radiographs (PIO) and the duration of asbestos exposure for 1,777 never smokers (NS), 4,550 current smokers, and 2,393 ex-smokers. RESULTS: Asbestos exposure in NS men decreased expiratory flows and increased TLCs compared with unexposed NS men. Further reductions in flows and FVC and increases RV/TLC with radiographic asbestosis were not statistically significant. As the PIO increased from 1/1 to 3/3, obstruction and air trapping increased significantly but TLC did not. CONCLUSIONS: Asbestos exposure reduced flows and produced air trapping after 20 years in workers who never smoked. Smoking increased these abnormalities.

Adult↗
PubMed1993

A reproducible trigger for the measurement of trigeminal latencies elicited by a glabellar tap.

In order to develop a screening test of trigeminal latencies which could be used in the field, a stimulator which delivered a "tap" consisting of a focused puff of air to the glabella was compared with a tap delivered by means of a lightweight hammer with a piezoelectric trigger similar to that described by Shahani (Shahani and Young, 1972, Neurology 22, 149-154). Results were similar for both methods although the mechanical tap failed to elicit a response from the left side in one subject. The benefit of the air tap is in the reproducible force of the tap and better aim than is possible with the hammer.

Blinking↗
PubMed1993

Measuring lung volumes in advanced asbestosis: comparability of plethysmographic and radiographic versus helium rebreathing and single breath methods.

Total lung capacity was measured in 16 workers with pulmonary asbestosis using four standard methods: body plethysmography, radiographic lung area, helium dilution by multiple breath and by single breath (alveolar volume). All men had irregular opacities of ILO profusion category 2/1 or greater and four had pleural plaques in addition. The radiographic and plethysmographic methods produced virtually identical mean values for TLC of 7.52 l and 7.64 l and for RV of 4.06 l and 4.32 l and all values were larger than those by helium dilution. The closed circuit helium dilution method systematically underestimated TLC with a mean of 5.89 l as did single breath helium dilution with a mean of 6.39 l. These men had a larger mean RV/TLC, measuring 56.9% by body plethysmography and 54.6% by X-ray area than by the rebreathing dilutional method which was 43.8%. Air trapping within a normal TLC which characterizes asbestosis is revealed by radiographic and plethysmographic methods but concealed by gas dilution methods. Use of the latter is at least partly responsible for the impression that asbestosis is a 'restrictive disease'.

Aged↗
PubMed1993

Neurobehavioral testing of subjects exposed residentially to groundwater contaminated from an aluminum die-casting plant and local referents.

Residents adjoining a die-casting plant had excessive headaches, numbness of hands and feet, dizziness, blurred vision, staggering, sweating, abnormal heart rhythm, and depression, which led to measurements of neurobehavioral performance, affective status, and the frequency of symptoms. They had all been exposed via well water and proximity to the plant to volatile organic chemicals (VOC) and to polychlorinated biphenyls (PCBs). The 117 exposed women and men and 46 unexposed referents were studied together for simple and choice visual reaction time, body sway speed, blink reflex latency, color discrimination, Culture Fair (a nonverbal nonarithmetic intelligence test), recall of stories, figures, and numbers, cognitive and psychomotor control (slotted pegboard and trail making A and B), long-term memory, profile of mood states (POMS), and scores and frequencies of 34 symptoms. Choice reaction time, sway speed, and blink latency were impaired in both sexes of the exposed group and trail making B was impaired in exposed women. The POMS scores and frequencies of 30 of 34 symptoms were elevated in both sexes, compared to referents. Recall, long-term memory, psychomotor speed, and other cognitive function tests were reduced in exposed subjects and in the referents as compared to national referents. Neurophysiological impairment, and cognitive and psychomotor dysfunction and affective disorders, especially depression and excessive frequency of symptoms, were associated with the use of wells contaminated with VOCs, TCE and PCBs.

Adolescent↗