The UCLA population studies of chronic obstructive respiratory disease. 9. Lung function changes associated with chronic exposure to photochemical oxidants; a cohort study among never-smokers.

Two cohorts of never-smoking residents of Los Angeles were studied on two occasions five years apart. One cohort (N = 1,099) lived in a community with moderate levels of photochemical pollution and low levels of other pollutants, and the second (N = 1,117) lived in a community with very high levels of photochemical oxidant and relatively high levels of sulfates and particulates. Studies included measurement of forced expiratory volumes and flow rates and single-breath nitrogen washout, as well as use of a standardized questionnaire. The data represent 47 percent of 2,340 and 58 percent of 1,935 residents, respectively, of the original community samples. Mean baseline spirometry and nitrogen washout for those who were and those who were not retested were similar, reflecting the fact that loss to follow-up was primarily due to changes of residence. In the more polluted area there were significantly worse lung function test results for both men and women at baseline and significantly more rapid deterioration at follow-up. Mean changes in nitrogen washout were significantly greater in the more polluted community for both sexes and for all age groups including children. Most of the spirometric test results showed significantly more rapid decline among adults in the more polluted community. These results are consistent with the hypothesis that chronic exposures to a mix of photochemical oxidants, sulfates and particulates are associated with increased loss of lung function, which is especially marked among tests that reflect function of the small airways.

Movement of labelled decamethonium in muscle fibres of the rat.

1. Tritium-labelled decamethonium accumulated in diaphragm muscles of the rat in vitro with a peak at the end-plate region and the distributions were fitted by Gaussian curves. 2. Prolonged wash in physiological saline (10 hr) produced some loss in radioactivity but no detectable spread of the labelled compound along the fibres, which indicated that the decamethonium was not in a mobile form. 3. Rats injected with labelled decamethonium showed radioactivity in the diaphragm muscles after 21 days. 4. A slow spread of the labelled compound along the fibres was detected, and from the widening of the Gaussian curves the apparent diffusion coefficient was 1.2 X 10(-8) cm2sec-1, which is less than 1/500 of that in free solution.

The UCLA population studies of chronic obstructive respiratory disease. VI. Relationship of physiologic factors to rate of change in forced expiratory volume in one second and forced vital capacity.

The mean annualized changes in height (delta height), in forced expiratory volume in one second (delta FEV1), and in forced vital capacity (delta FVC), measured at a 5-yr interval, were determined by year of age for 1,458 residents 7 to 59 yr of age in 2 communities in Los Angeles. The rate of change in delta height, delta FEV1, and delta FVC increased each year until early puberty and then decreased thereafter. The age at which the delta FEV1 and delta FVC reversed from an increasing to a decreasing rate was older in males (13 yr) than in females (11 yr) and lagged about 1 yr behind the age at which rate of delta height reversed. The rate of delta FEV1 and delta FVC sharply declined thereafter until the early 20s, at which age the rate of change leveled off to a constant value. The age at which the delta FEV1 and delta FVC reversed from positive to negative ranged from 21 to 23+ yr, but was probably of less importance physiologically than the age at which the rate of change in delta FEV1 and delta FVC leveled off. The results suggest that growth factors are the major determinants for changes in delta FEV1 and delta FVC until the late teens. From the until the mid-20s, both growth factors and physiologic deterioration may affect delta FEV1 and delta FVC. Thereafter, the primary determinant of delta FEV1 and delta FVC appears to be a gradual but steady decline in physiologic status.

The UCLA population studies of chronic obstructive respiratory disease. I. Methodology and comparison of lung function in areas of high and low pollution.

The prevalence of symptoms of chronic obstructive respiratory disease and of functional respiratory impairment was determined in 3465 residents (70 per cent of enumerated) of an area historically exposed to photochemical/oxidant pollutants and 4509 residents (79 per cent of enumerated) of an area exposed to low levels of chemical pollutants. Tests administered included the NHLI questionnaire, electronic volume spirometry, whole body plethysmography, and the single-breath nitrogen test (deltaN2750-1250 and closing volume). Cough and cough with sputum were more frequently reported in the low-pollution area. Lung function was better among residents of the low-pollution area according to FEV1, FVC, maximal expiratory flow rates, closing volume fraction, thoracic gas volume, and airway resistance. Maximal mid-expiratory flow rate, considered to be a sensitive spirometric test for detection of small airways disease, was similar in residents of both areas. Mean deltaN2750-1250 was slightly worse among residents of the low-pollution area. Findings suggest that adverse effects of long-term exposure to photochemical/oxidant pollutants may occur primarily in the larger airways both among smokers and never smokers. The greatest differences between areas were observed in residents 18-59 years of age, suggesting that long-term exposure may be required to cause measurable impairment and that these differnces may be obliterated by such factors as smoking, differential out-migration and differential survival.

The UCLA population studies of CORD: X. A cohort study of changes in respiratory function associated with chronic exposure to SOx, NOx, and hydrocarbons.

Two never-smoking cohorts in Southern California, one in Lancaster (N = 2340) exposed only to moderate levels of oxidants and the other in Long Beach (N = 1326) exposed to high levels of SOx, NO2, hydrocarbons and particulates completed spirometry and the single-breath nitrogen test five to six years apart. Forty-seven percent and 45 percent of the participants were retested. Mean results at baseline for those tested and not retested were similar. Loss to follow-up was primarily due to moving (39 percent and 47 percent). Every difference of consequence indicated greater deterioration in lung function in Long Beach. The level of significance of the difference was greatest, even in the youngest age groups, for delta N2(750-1250), suggesting that the earliest site of impairment may occur in the small airways. Greater deterioration in spirometric parameters was observed in every age group in Long Beach females above seven years of age at baseline and in Long Beach males above 15 years of age, suggesting that chronic exposure to the pollutant mix occurring in Long Beach ultimately adversely affects the large airways as well as small airways.

The UCLA population studies of chronic obstructive respiratory disease. IV. Respiratory effect of long-term exposure to photochemical oxidants, nitrogen dioxide, and sulfates on current and never smokers.

Questionnaires, spirometry, and the single-breath nitrogen test were administered to 3,192 participants 25 to 39 yr of age in area exposed to low concentrations of all pollutants (Lancaster, California) and to 2,369 similar participants living in an area exposed to high concentrations of photochemical oxidants, nitrogen dioxide, and sulfates (Glendora, California). The prevalence of symptoms and results in the majority of the tests were worse in the polluted area between current and never smokers and men and women. Those tests associated primarily with small airways (Vmax50, Vmax75, delta N 2(750-1250) showed little or no difference between areas. The difference in the prevalence of participants with a poor FEV1 and/or poor FEV1 and/or poor FVC and in the mean Vmax and closing volume was greater between areas than between smoking categories. These results suggest that long-term exposure to high concentrations of photochemical oxidants, NO2, and sulfates at place of residence may result in measurable impairment in both current smokers and never smokers. Firmer documentation of this effect will require following these populations for changes in lung function that correlate with pollutant exposures.

Subclinical effects of chronic increased lead absorption--a prospective study. I. Study design and analysis of symptoms.

Seventy workers exposed to lead for at least one year and 35 control workers have been enrolled in a prospective study of possible neurologic effects of chronic lead absorption at or below the current standard of 80 microgram per 100 ml whole blood. The study design is described in detail. Initial results of analysis of lead-related symptoms from baseline studies indicate few differences between the exposed and nonexposed workers. The majority of differences were for central nervous system (CNS) symptoms and muscle or joint pain. Little correlation was found between symptom reporting and indices of lead absorption. The evidence suggests that factors other than lead absorption itself may be important in symptom reporting.

Vasectomy and health. Results from a large cohort study.

In this historical cohort study we identified, located, and, if living, interviewed 10,590 vasectomized men from four cities, along with a paired neighborhood control for each. The times between procedure data and interview or death ranged from under one to 41 years, with median equal to 7.9 years and with 2,318 pairs having ten or more years of follow-up. Participant reports of diseases or conditions that might possibly be related to vasectomy through an immunopathological mechanism were validated by direct contact with physicians and review of medical records. Results of this study do not support the suggestions of immunopathological consequences of vasectomy within the period of follow-up. Except for epididymitis-orchitis, the incidence of diseases for vasectomized men was similar or lower than for their paired controls.

Subclinical effects of chronic increased lead absorption--a prospective study. II. Results of baseline neurologic testing.

This report summarizes the results of baseline neurologic testing in a group of apparently healthy workers from a secondary lead smelter and a group of controls from nearby aluminum processing plants. The test battery included a standard neurologic examination nerve conduction measurements, quantitative oculomotor function tests and detailed audiologic studies. Lead workers and controls were intermixed so that the examiners were unaware of the status of any individual being tested. Although the lead workers reported significantly more neurologic symptoms than the controls, relatively few differences were found on quantitative neurologic testing. Decreased deep tendon reflexes occured more frequently in the lead workers than in the controls (22% vs. 11%) but the difference was of borderline significance (p=0.06) and other signs of peripheral neuropathy occurred with equal frequency in both groups. The mean motor conduction velocity and sensory latency measurements were not significantly different in the lead workers and in the controls and, of the six oculomotor function measurements, only the mean accuracy of saccadic eye movements was significantly (p less than 0.01) different in the two groups. High frequency hearing loss occurred with equal frequency and severity in both groups, consistent with the level of noise exposure in the lead and control plants.