Meeting Report: Aging Research and Drug Discovery

Aging is the single largest risk factor for most chronic diseases, and thus possesses large socioeconomic interest to continuously aging societies. Consequently, the field of aging research is expanding alongside a growing focus from the industry and investors in aging research. This year’s 8th Annual Aging Research and Drug Discovery (ARDD) meeting was organized as a hybrid meeting from August 30th to September 3rd 2021 with more than 130 attendees participating on-site at the Ceremonial Hall at University of Copenhagen, Denmark, and 1800 engaging online. The conference comprised of presentations from 75 speakers focusing on new research in topics including mechanisms of aging and how these can be modulated as well as the use of AI and new standards of practices within aging research. This year, a longevity workshop was included to build stronger connections with the clinical community.

Effect of systemic transplantation of bone marrow-derived mesenchymal stem cells on neuropathology markers in APP/PS1 Alzheimer mice

AIMS

Mesenchymal stem cells (MSC) have recently attracted interest as a potential basis for a cell-based therapy of AD. We investigated the putative immune-modulatory effects in neuroinflammation of systemic transplantation of MSC into APP/PS1 transgenic mice.

METHODS

10⁶ MSC were injected into APP/PS1 mice via the tail vein and histological analysis was performed for microglia and amyloid (pE3-Aβ) plaque numbers, glial distribution and pE3-Aβ plaque size. In addition, a biochemical analysis by qPCR for pro-inflammatory, chemoattractant and neurotrophic factors was performed.

RESULTS

MSC are associated with pE3-Aβ plaques. The effects of transplantation on microglia-associated pathology could be observed after 28 days. Animals showed a reduction in microglial numbers in the cortex and in microglia size. Gene expression was reduced for TNF-α, IL-6, MCP-1, and for NGF, in MSC recipients. Also, we investigated for the first time and found no changes in expression of IL-10, CCR5, BDNF, VEGF and IFNγ. PTGER2 expression levels were increased in the hippocampus but were reduced in the cortex of MSC recipients. While there were no transplant-related changes in pE3-Aβ plaque numbers, a reduction in the size of pE3-Aβ plaques was observed in the hippocampus of transplant recipients.

CONCLUSION

This is the first study to show reduction in pE3-Aβ plaque size. pE3-Aβ plaques have gained attention as potential key participants in AD due to their increased aggregation propensity, the possibility for the initial seeding event, resistance against degradation and neurotoxicity. These findings support the hypothesis that MSC-transplants may affect AD pathology via an immune-modulatory function that includes an effect on microglial cells.

Abstract 2972: Intestinal p53 deletion leads to accumulation of chromosomal instability without promoting tumor formation

Background:

Colorectal cancer is after lung cancer the second biggest cancer threat for humans and the tumor burden is rising steadily during human ageing. One important issue during human ageing is the accumulation of DNA damage inducing a p53 dependent response leading to p21-dependent senescence or apoptosis. It has been shown that deletion of DNA repair proteins as well as other components of the DNA damage pathway leads to tumor formation.

Methods:

In this approach we investigated the role of the tumor suppressor p53 with and without telomere dysfunction in intestinal tumor formation. Late generation of iG4 mTerc−/−; p53lox/lox and iF1 mTerc+/− p53lox/lox mice were crossed to Villin-Cre-ERT2 transgenic mouse model. In 1 month old mice Tamoxifen was injected on 5 consecutive days leading to functional deletion of the Trp53 gene.

Results:

In aging IF1 Terc+/− p53 deletion did not induce an obvious intestinal phenotype including tumor formation until 24 months. In contrast to p21 deletion the deletion of p53 significantly shortened the lifespan of iG4 Terc−/− Trp53−/− animals compared to iG4 Terc−/− Trp53+/+. This reduction correlated with earlier appearance of crypt atrophy and weight loss but was not associated with tumor formation. Deletion of the Trp53 gene resulted in an abrogation of the p21-dependent senescence and accumulation of DNA damage in the intestinal epithelium of both p53 deleted cohorts. Moreover this correlated with an accumulation of intestinal stem cells carrying high levels of DNA damage. On contrary to p21 deletion the deletion of p53 impaired the depletion of chromosomal instable intestinal stem cells in aging telomere dysfunctional mice.

Conclusion:

These results provide first proof that deletion of p53 is not able to promote tumorigenesis in the intestinal epithelium of mice and that p53 induction has a protective role preventing accumulation of damaged intestinal stem cells in aging telomere dysfunctional mice.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2972.

Short telomeres and prognosis of hypertension in a chinese population

Aging is a major risk factor for hypertension and cardiovascular disease. Accumulating evidence suggests that telomere length is a marker for biological aging of the cardiovascular system. Telomere length is determined by genetic and environmental factors. Studies in different racial populations are required to determine the prognostic value of telomere length in hypertension and cardiovascular diseases. The main objective of this study was to investigate the association between leukocyte telomere length and the risk and prognosis of hypertension in a Chinese population. The relative telomere length of leukocytes was determined by a quantitative PCR-based method in 767 subjects: 379 healthy controls and 388 hypertensive patients, ages 30 to 80 years. The median telomere length ratio, 0.57 (interquartile range: 0.48 to 0.72), was shorter in hypertensive than in healthy normotensive subjects (0.67; interquartile range: 0.53 to 0.93; P<0.001). After 5 years of follow-up, subjects with shorter telomeres were at a higher risk of developing coronary artery disease than individuals with longer telomeres (odds ratio: 3.315; 95% CI: 1.662 to 6.609; P<0.001). Multivariate analysis showed that short telomere length and hypertension were independent risk factors for developing coronary artery disease. Our data suggest that mean leukocyte telomere length is a potential predictor of coronary artery disease and support the hypothesis that differences in biological aging can contribute to the risk and variability of developing hypertension and cardiovascular diseases.

Diagnosis and treatment of hepatocellular carcinoma

The diagnosis and treatment of hepatocellular carcinoma (HCC) have witnessed major changes over the past decade. Until the early 1990s, HCC was a relatively rare malignancy, typically diagnosed at an advanced stage in a symptomatic patient, and there were no known effective palliative or therapeutic options. However, the rising incidence of HCC in several regions around the world coupled with emerging evidence for efficacy of screening in high-risk patients, liver transplantation as a curative option in select patients, ability to make definitive diagnosis using high-resolution imaging of the liver, less dependency on obtaining tissue diagnosis, and proven efficacy of transarterial chemoembolization and sorafenib as palliative therapy have improved the outlook for HCC patients. In this article, we present a summary of the most recent information on screening, diagnosis, staging, and different treatment modalities of HCC, as well as our recommended management approach.

Psychosocial job factors and return-to-work after compensated low back injury: a disability phase-specific analysis

BACKGROUND

Job characteristics may constitute a barrier to return-to-work (RTW) after compensated disabling low back pain (LBP). This study examines the impact of psychosocial job factors on time to RTW separately during the acute and subacute/chronic disability phases.

METHODS

This is a retrospective cohort study of 433 LBP workers' compensation claimants with 1-4 years of follow-up. The association of psychosocial job factors with duration of work disability was estimated with Cox regression models, adjusting for injury history and severity, physical workload, and demographic and employment factors.

RESULTS

High physical and psychological job demands and low supervisory support are each associated with about 20% lower RTW rates during all disability phases. High job control, especially control over work and rest periods, is associated with over 30% higher RTW rates, but only during the subacute/chronic disability phase starting 30 days after injury. Job satisfaction and coworker support are unrelated to time to RTW.

CONCLUSIONS

Duration of work disability is associated with psychosocial job factors independent of injury severity and physical workload. The impact of these risk factors changes significantly over the course of disability.

Integrating occupational health services and occupational prevention services

BACKGROUND

Despite the human and monetary costs of occupational injury and illness, occupational health care has focused more on treatment than prevention, and prevention is not part of many clinical occupational health practices. This represents a failure of occupational health care to meet the health care needs of the working patients.

METHODS

MEDLINE searches were conducted for literature on occupational medical treatment and the prevention of occupational injury and illness were reviewed to for linkages between prevention and treatment. Policy discussions which identify examples of programs that integrated prevention and treatment were included.

RESULTS

Although examples of the integration of clinical and preventive occupational health services exist, there are challenges and barriers to such integration. These include inaction by clinicians who do not recognize their potential role in prevention; the absence of a relationship between the clinician and an employer willing to participate in prevention; economic disincentives against prevention; and the absence of tools that evaluate clinicians on their performance in prevention.

CONCLUSIONS

Research is needed to improve and promote clinical occupational health preventive services.

Doctor proactive communication, return-to-work recommendation, and duration of disability after a workers' compensation low back injury

Although doctors are increasingly evaluated on the basis of return-to-work (RTW) outcomes, the effect of doctor-patient communication about the workplace and RTW after an occupational injury has received little research attention. The effect of patient-reported doctor communication on duration of disability was examined retrospectively in a 3-year cohort of 325 claimants with a lost-time low back injury. Although doctor proactive communication was associated with a greater likelihood of RTW during the acute phase (< 30 days of disability), this effect disappeared when injury and workload characteristics were taken into account. A positive RTW recommendation was associated with about a 60% higher RTW rate during the subacute/chronic phase (> 30 days of disability) only. Prospective studies are needed to confirm this effect. The impact of physician communication on RTW is largely confounded by injury and workplace factors.

Physical workplace factors and return to work after compensated low back injury: a disability phase-specific analysis

Little is known about predictors of duration of work disability (DOD). This cohort study of 433 workers' compensation claimants estimated DOD for job, injury, and demographic factors during consecutive disability phases using Cox regression analysis. DOD was calculated from administrative records. Results show that DOD increases with the time spent bending and lifting or pushing or pulling heavy objects at work, but it is unrelated to sitting, standing, or vibration. Younger age, longer pre-injury employment, less severe injuries, and a previous back injury predicted shorter disability, the latter factor only during the subacute/chronic disability phases. The effect of injury severity decayed over time. This study demonstrates the usefulness of a phase-specific analysis and shows that physical job and injury factors have a significant and time-varying impact on DOD.

Recommendations to guide revision of the Guides to the Evaluation of Permanent Impairment. American Medical Association

The American Medical Association's Guides to the Evaluation of Permanent Impairment, Fourth Edition, is the most commonly used tool in the United States for rating permanent impairments for disability systems. The Guides, currently undergoing revision, has been the focus of considerable controversy. Criticisms have focused on 2 areas: internal deficiencies, including the lack of a comprehensive, valid, reliable, unbiased, and evidence-based system for rating impairments; and the way in which workers' compensation systems use the ratings, resulting in inappropriate compensation. We focus on the internal deficiencies and recommend that the Guides remains a tool for evaluation of permanent impairment, not disability. To maintain wide acceptance of the Guides, its authors need to improve the validity, internal consistency, and comprehensiveness of the ratings; document reliability and reproducibility of the results; and make the Guides easily comprehensible and accessible to physicians.

Duration of work disability after low back injury: a comparison of administrative and self-reported outcomes

BACKGROUND

Workers' compensation wage replacement data have recently been used to estimate time to return to work (RTW) and the number of work days lost after occupational injury. The degree to which indemnity-based measures reflect self-reported work disability has until now not been studied.

METHOD

Kaplan-Meier curves of administrative and self-reported measures of duration of work disability were compared within a sample of 433 low back injury claimants followed up for 1 to 3.7 years.

RESULTS

Administrative measures consistently and significantly underestimated the duration of disability when compared to self-reported measures of RTW. The difference between the estimated mean number of work days lost for comparable administrative and self-reported measures ranged from 142 to 334 days.

CONCLUSIONS

Number of work days lost after low back injury is substantially underestimated by measures based on the duration of wage replacement benefits. This calls into question the adequacy of indemnity benefits and underscores the need for disability prevention programs.

Design of a state-based workers' compensation information system

BACKGROUND

California policy makers have long been hampered by a lack of credible information for use in making legislative or administrative changes to address serious problems in the workers' compensation system. In 1993, the legislature directed the California Division of Workers' Compensation to develop a Workers' Compensation Information System (WCIS).

METHODS

An advisory committee developed key questions and identified data sources regarding injury/illness incidence, costs, promptness of benefit delivery, adequacy of benefits, satisfaction with services, and other outcomes.

RESULTS

Key data elements were identified, mostly from existing mandated reporting forms for employers and physicians, and from standardized medical billings. Data collection will be carried out using: 1) rapid electronic data interchange (EDI) for a minimum number of data elements; 2) electronic collection of data on medical services for a sample of claims; and 3) surveys to address adequacy of benefits, satisfaction with services, return to work, and other outcomes. A state-based repository will analyze data and provide de-identified public use data files.

CONCLUSIONS

The proposed WCIS will provide information to improve the performance and to increase the accountability of all the participants in California's Workers' Compensation system. More importantly, it will provide information which will allow improved quality in the provision of mandated benefits to injured workers.

Alternative approaches for measuring duration of work disability after low back injury based on administrative workers' compensation data

BACKGROUND

Studies of low back pain (LBP) disability remain largely incomparable because of different outcome definitions. To date, systematic comparisons of alternative outcome measures have not been made.

METHODS

Duration of work disability was studied in a 3-year cohort of 850 workers' compensation LBP claimants. Eleven administrative outcome measures were compared using Kaplan-Meier estimates of the proportion of claimants still on disability benefits during 3.5 years of follow-up.

RESULTS

The estimated mean duration of work disability was 75 days for the first temporary disability (TD) episode, 108 days for cumulative time on TD, and 337 for total compensated days, which includes all types of wage replacement benefits during vocational rehabilitation, temporary and permanent disability.

CONCLUSIONS

Commonly used administrative measures of lost workdays--time to first return to work and time on temporary disability--substantially underestimate the duration of work disability compared to measures based on all wage replacement benefits.

Performance measures in occupational medicine: a tool to manage quality

Managed care in occupational medicine has cut costs of workers' compensation. However, quality of care may have received less-than-optimal attention. The use of quality indicators is a new phenomenon.

The role of prevention in workers' compensation managed care arrangements

Managed care's emphasis on restricting costs may interfere with its ability to assume a prevention orientation. The authors present models, derived from group health and workers' compensation, of successful incorporation of prevention into managed care arrangements.

Non-human primate models; artificial menstrual cycles, endometrial matrix metalloproteinases and s.c. endometrial grafts

Rhesus monkeys are useful models in which to examine the hormonal regulation of endometrial matrix metalloproteinases (MMP) and to evaluate the role of MMP in uterine bleeding. Artificial 28 day menstrual cycles can be induced in ovariectomized monkeys by inserting an oestradiol implant for 2 weeks, then inserting a progesterone implant for 2 weeks, and then, with the oestradiol implant remaining in place, removing and reinserting the progesterone implant at 2 week intervals. To examine MMP during menses, we established such cycles and removed uteri by hysterectomy at closely spaced intervals before, during and after menses, as well as at later time points. Some samples were also obtained during menses induced by the withdrawal of both progesterone and oestradiol. We examined mRNA of the following MMP by Northern blotting: matrilysin, stromelysin-1, stromelysin-2, stromelysin-3 and the tissue inhibitor of MMP TIMP-1. The expression of these MMP mRNA increased substantially by 2-3 days after progesterone withdrawal, whether or not oestradiol was maintained. The expression of some of the MMP (stromelysins-1 and -2) returned very rapidly to baseline levels by 5 days after progesterone withdrawal, while the expression of others (matrilysin, stromelysin-3 and TIMP-1) declined more slowly, reaching a baseline level by 10 days after progesterone withdrawal, with little or no further decline after progesterone concentrations rose during the induced luteal phase. Immunocytochemical studies showed that matrilysin was expressed primarily in the glands of the upper functionalis. In other work with the rhesus monkey model, we used a s.c. endometrial autograft technique in which pieces of endometrium were autotransplanted to the abdominal skin. During menses in the grafts, matrilysin was expressed in the glands of the grafts similar to the glands in the eutopic endometrium. Endometrial autografts can serve as a useful model for the study of MMP in uterine bleeding.

The surveillance of work-related pesticide illness: an application of the Sentinel Event Notification System for Occupational Risks (SENSOR)

OBJECTIVES

In response to limitations in state-based occupational disease surveillance, the California Department of Health Services developed a model for surveillance of acute, work-related pesticide illness. The objectives were to enhance case reporting and link case reports to preventive interventions.

METHODS

Elements from surveillance of communicable diseases and sentinel health events were used to integrate a model into the preexisting system in one agricultural country.

RESULTS

Between 1988 and 1991, 45 Fresno County health care providers reported 230 suspected cases, of which 217 from 80 work sites met reporting guidelines. Risk factors were profiled from interviews of 81 prioritized case patients and 36 employers. Fifteen work sites were visited and 117 recommendations were made, of which 6% were identified in enforcement inspections. Pest management experts consulted with growers on reducing future pesticide use.

CONCLUSIONS

Risk factors for pesticide illness were prevalent. Agricultural inspectors did not detect routine and serious hazards. Integrated pest management should be expanded and linked to occupational health. Agricultural enforcement personnel should be oriented and trained in occupational safety and health.

Surveillance and prevention of work-related carpal tunnel syndrome: an application of the Sentinel Events Notification System for Occupational Risks

In response to limitations in state-based, occupational disease surveillance, the California Department of Health Services developed a model for provider- and case-based surveillance of work-related carpal tunnel syndrome. The objectives were to enhance case reporting, identify risk factors and high-risk work sites, and link preventive interventions to work sites and the broader community. Using elements from surveillance of communicable diseases and sentinel health events, a model was integrated into the pre-existing reporting system in one California county. Between 1989 and 1991, 54 Santa Clara County health care providers reported 382 suspected cases, of which 365 from 195 work sites met reporting guidelines. Risk factors were profiled from interviews of 135 prioritized cases and 38 employers. Of 24 work sites prioritized for a free, voluntary, nonenforcement inspection, 18 refused and 6 completed an on-site visit. Sentinel Event Notification System for Occupational Risks (SENSOR) captured many cases not reported to the pre-existing reporting system. Case interviews indicated a profile of symptoms and signs, treatment, and exposure to uncontrolled occupational risk factors, including a lack of training on ergonomics hazards. Employer health insurance, rather than workers' compensation, was the apparent source of payment for most medical bills. Employers lacked knowledge and motivation to reduce ergonomic risks. Governmentally mandated occupational ergonomics standards are urgently needed.

Demographic and diagnostic characteristics of inmates receiving mental health services in state adult correctional facilities: United States, 1988

The demographic and diagnostic characteristics of inmates in State adult correctional facilities who received 24-hour hospital mental health care, residential treatment care, and counseling/therapy in 1988 are reported by State and by type of administrative auspices under which the services are provided. Rates under treatment for 24-hour hospital mental health care were highest for the youngest (under 18) and oldest (65 and over) age groups, for females, and for whites. For counseling/therapy, rates were also highest for the youngest, for females, and for whites, but they declined with age. Rates in residential treatment were highest for the young and old and for whites, but about equal for males and females. Primary diagnoses of major psychoses predominated in 24-hour hospital mental health care. In residential treatment, a comparatively small proportion of the caseload had major psychotic disorders and a comparatively large proportion had substance abuse and mental retardation diagnoses. In counseling/therapy, personality disorders predominated. Individual State figures vary widely on these characteristics, both within and between service auspice types.

Funding, expenditures, and staffing of mental health services in state adult correctional facilities: United States, 1988

State-by-State data concerning the sources of funding, expenditures, and staffing for mental health services in State correctional facilities are reported for 1988 from the first national survey of prison mental health services conducted by the Center for Mental Health Services. Among all States, the total annual funding per prison inmate for mental health services varied widely, ranging from $5.67 to $3,159.41 per inmate, with a mean of $469.67 and median of $303.48 per inmate. States that administered 24-hour hospital mental health care to prisoners solely through the Department of Corrections (DOC) also tended to fund all types of mental health services solely through the DOC. However, in States where the Department of Mental Health (DMH) had primary administrative responsibility for 24-hour hospital mental health care, funding sources for all types of mental health services available to prison inmates were more likely to be mixed--i.e., funded through DOC as well as through DMH and other administrative entities. Master's-level mental health providers outnumbered doctoral-level professionals by more than two to one. At both of these educational levels, psychologists were numerically the largest category of provider, followed by social workers among master's-trained professionals, and followed by psychiatrists among those with doctorates. The single largest category was mental health workers with bachelor's-level training or less; this group accounted for about 44 percent of all mental health staff on State prison payrolls.

Overview of mental health services provided by state adult correctional facilities: United States, 1988

State-by-State data concerning the administrative auspices, volume of use, and sources of funding and expenditures for mental health services in adult correctional facilities are reported for 1988 from the first national survey of prison mental health services conducted by the Center for Mental Health Services. In all States reporting, a total of 11,546 State prison inmates--about 25 per 1,000--were receiving 24-hour psychiatric inpatient or residential treatment care for a psychiatric disorder on September 30, 1988. During the month of September 1988, nearly 10 percent of State prison inmates (95.6 per thousand) received some form of mental health counseling or psychotherapy from a physician, nurse, psychologist, or social worker; about 5 percent (49.7 per thousand inmates) received monitoring or evaluation of a psychotropic medications regimen; and about 4 percent (41.7 per thousand inmates) received psychiatric assessment or psychological testing to determine their mental health or emotional status. In the majority of States, 24-hour mental health care was provided in a mix of psychiatric and prison hospital settings, both on and off prison grounds, through interagency agreements, or through a mix of interagency and contractual arrangements. Individual State figures vary widely on these characteristics, as well as on length of stay for 24-hour hospital and residential treatment care, both within and among auspice types.

The initial impact of a workplace lead-poisoning prevention project

The California Department of Health Services began an occupational lead poisoning prevention project in cooperation with 275 radiator service companies. The agency developed and marketed resources to facilitate companies' own efforts, tracked the progress of each company, and urged the companies to conduct blood lead testing. Testing by participating employers increased from 9% to 95%, and 10 times as many companies with likely overexposures were identified as had been reported to the state's lead registry in the previous year. The success of this project indicates that the model should be applied more extensively.

California adults with elevated blood lead levels, 1987 through 1990

OBJECTIVES

Follow-up of California blood lead registry reports, 95% of which are of occupationally exposed adults, can guide interventions at specific high-risk work sites and measure the impact of targeted, industry-specific interventions.

METHODS

A protocol was implemented to follow up the most severe case reports (> or = 2.90 mumol/L) and establish a statistical database for descriptive analysis.

RESULTS

From 1987 through 1990, the California Department of Health Services received 17,951 reports for 4069 civilian, noninstitutionalized adults employed by at least 328 companies. Of 232 incident case subjects with severe lead toxicity (> or = 2.90 mumol/L), 182 were successfully traced and interviewed. Index case subjects were mostly male (95%) and disproportionately Hispanic (46%); 35% lived with children aged 7 or younger, and 10% had been hospitalized. Ninety-four percent involved overexposures at work sites that lacked medical removal (50%), ventilation (36%), appropriate respirators (62%), training (64%), clothing changes (45%), or showering (60%).

CONCLUSIONS

Well-known risk factors for occupational lead poisoning clustered at the work sites of index case subjects. Despite standards of the Occupational Safety and Health Administration, lead overexposure in California adults remains a significant public and occupational health concern.

Issues in notification: reflections of a public health worker

The objectives of notification are to inform individuals of research results so that they can make informed choices regarding health care and risk reduction behaviors, and to inform workers and employers of results and recommendations in order to take actions to improve workplace health and safety. Many questions confront researchers or public health workers engaged in notification efforts. Who should be notified? What information should be included in notification materials? When should notification occur? How and where should notification take place? What is the socioeconomic context in which notification is occurring? This article presents a public health worker's perspective on these issues.

The identification of occupational lung disease from hospital discharge data

The Bureau of Labor Statistics-State Health Department Select Committee on Occupational Illnesses and Injuries conducted a study of hospital discharge records to determine their usefulness for identifying cases of occupational disease. Four states searched the diagnosis fields on computerized hospital discharge records for selected occupational lung diseases; pneumoconiosis, extrinsic allergic alveolitis, and respiratory conditions due to chemical fumes and vapors. The hospital discharge data identified more cases of pneumoconiosis than did the BLS data systems. Numerous cases of extrinsic allergic alveolitis and respiratory conditions due to chemical fumes and vapors were also identified. Patterns evidenced in the data were generally consistent with current knowledge of the diseases. The inclusion of industry and occupation on the hospital discharge record, further study of the quality of diagnosis coding, and the use of these data by additional states will enhance the usefulness of these data for occupational disease surveillance.

Design and methods for a survey of lead usage and exposure monitoring in California industry

A probability sample of California workplaces in 1986 estimated the numbers of workers using lead and their coverage by biological and environmental monitoring. Study steps included (1) identifying 505 stand ard industrial classifications (SICs) with possible lead use; (2) creating an employer lis; (3) identifying for oversampling seven single SICs and a group of 165 SICs with documented high ambient air lead; (4) further stratification by workforce size; (5) prediction from National Institute for Occupational Safety and Health surveys the number of lead-using workers for each employer; (6) drawing facilities into the sample with selection probability proportional to the number of workers predicted to use lead; (7) adjusting the sample selection if an employer listing covered multiple facilities; (8) sending a first-stage telephone/mail questionnaire to identify lead users, who were sent a second questionnaire; (10)follow-up which, aided by statutory authority, resulted in completion rates over 90%; (11) ranking lead-using processes by intensity of exposure; and (12) analysis. Sources of error include random sampling error, misleadingly large standard errors because sampling was with replacement, gaps in the employer list, and inaccurate responses. As a measure for the probability proportional to size sampling, total work force count would have been superior to the predicted number of lead users. Restriction to a single hazard makes a questionnaire-based study feasible, but names of workers, rather than counts, should be requested and a subsample should be visited.

Lead use in California industry: its prevalence and health implications

An estimated 230,000 workers were reported to work in lead-using activities as a result of a 1986 statistical survey of employers in California. However, 68% of these workers worked in activities of relatively low hazard. This included 114,000 workers engaged in electronic soldering. Over 1800 workers were reported to work in battery manufacture, a relatively high-hazard activity, but with consistent monitoring and protection. In contrast, over 4300 workers were involved in radiator repair activities, a high-hazard activity with inconsistent monitoring and protection. Over 8% of construction workers were reported to work in lead-using processes. This sector is exempt from federal Occupational Safety and Health Administration (Fed/OSHA) and California Occupational Safety and Health (Cal/OSHA) lead standards, yet some of the most hazardous activities (welding, grinding, and cutting, etc.) occurred here. Comparison of projections from the National Occupational Hazard Survey of potential lead exposure in California with these survey results suggests consistent and reliable assessment of the major sources of potential occupational exposure to lead.

Elevated blood lead in California adults, 1987: results of a statewide surveillance program based on laboratory reports

California medical laboratories that test for blood lead are required to report results exceeding 1.21 mumols/L (25 micrograms/dl). Between April and December 1987, the California Department of Health Services received 3,077 blood lead reports from 34 laboratories for 1,293 civilian, non-institutionalized adults. Approximately 1 percent of all reports exceeded 3.87 mumols/L (80 micrograms/dl), 7 percent exceeded 2.42 mumols/L (50 micrograms/dl), and 21 percent exceeded 1.93 mumols/L (40 micrograms/dl). Individuals tested were overwhelmingly male (94 percent), disproportionately Hispanic surnamed (44 percent), and most often residents of Los Angeles County (81 percent). Workers in lead smelting, battery manufacturing, and brass foundries accounted for nearly 80 percent of reports. Construction, radiator repair, pottery and ceramics manufacturing, and gun firing ranges accounted for the remainder. All adults with reports of greater than or equal to 2.90 mumols/L who were contacted reported on occupational exposure. Approximately half were not in routine medical monitoring programs. Despite OSHA standards, elevated blood lead with the potential for serious acute and chronic lead poisoning in California adults remains a significant public health and major occupational health concern.

Environmental and biological monitoring for lead exposure in California workplaces

Patterns of environmental and biological monitoring for lead exposure were surveyed in lead-using industries in California. Employer self-reporting indicates a large proportion of potentially lead-exposed workers have never participated in a monitoring program. Only 2.6 percent of facilities have done environmental monitoring for lead, and only 1.4 percent have routine biological monitoring programs. Monitoring practices vary by size of facility, with higher proportions in industries in which larger facilities predominate. Almost 80 percent of battery manufacturing employees work in job classifications which have been monitored, versus only 1 percent of radiator-repair workers. These findings suggest that laboratory-based surveillance for occupational lead poisoning may seriously underestimate the true number of lead poisoned workers and raise serious questions regarding compliance with key elements of the OSHA Lead Standard.

The worker's perspective

The author recommends involvement of workers in every phase of epidemiologic research or clinical surveillance programs, from hypothesis generation and study design through interpretation of results and discussion of recommendations for notification, counseling, and intervention. Clinicians must be aware of the potential work-relatedness of illness and routinely obtain an occupational history.

Reproductive hazards in the microelectronics industry

There has been increased awareness of the potential for occupational and environmental exposures to hazardous substances to adversely affect reproductive outcome in men and women. The purpose of this article is to familiarize the clinician with some of the normal physiologic changes of pregnancy and how those may interact with working conditions in the electronics industry. It also reviews some of the data regarding potential reproductive hazards of substances and physical agents used in this industry.

Intraarterial cis-platinum chemotherapy for patients with primary and metastatic brain tumors

A total of 49 patients were treated using intraarterial cis-platinum infusions at a dose of 100 mg/m2. The patients were separated into three groups. There were 13 patients with metastatic tumors, 10 with recurrent malignant gliomas, and 22 patients with high-grade gliomas who received intraarterial cis-platinum as part of an adjuvant program. In addition, four nongliomatous primary brain tumors were treated in this fashion. Cis-platinum was filtered immediately prior to intraarterial infusion using a 0.22-micron filter. Response to treatment was evaluated by follow-up CAT scans and neurologic examinations. There were three complete and eight partial responses in metastatic tumors, and eight partial responses in recurrent gliomas. The median survival was 19 weeks for patients with metastatic disease, and 16 weeks for patients with recurrent gliomas. Those high-grade glioma patients who received intraarterial cis-platinum as adjuvant chemotherapy along with CCNU and radiation therapy had a projected median survival of 91+ weeks. Toxicity from intraarterial cis-platinum following drug filtration was markedly reduced when compared with previous reports. Only five patients experiencing visual or central nervous system toxicity utilizing filtered cis-platinum and no radiographic or histopathologic evidence of central nervous system toxicity was observed. Bilateral deafness was observed following vertebral artery infusion in both patients treated in this manner and thus vertebral artery infusions should be avoided. Systemic toxicity was mild. Intracarotid infusion is a safe, well-tolerated delivery system for filtered cis-platinum with a high response rate for patients with both metastatic and primary malignant brain tumors.