PHvol3 5/22/03 3:23 PM Page 1 Encyclopedia of Public Health Editorial Board EDITOR IN CHIEF Lester Breslow, University of California at Los Angeles, School of Public Health ASSOCIATE EDITORS Bernard D. Goldstein, Graduate School of Public Health, University of Pittsburgh Lawrence W. Green, Centers for Disease Control and Prevention C. William Keck, Akron, Ohio, Health Department John M. Last, University of Ottawa Michael McGinnis, The Robert Wood Johnson Foundation ii PHvol3 5/22/03 3:23 PM Page 3 Encyclopedia of Public Health Edited by Lester Breslow Volume 3 L-R Copyright © 2002 by Macmillan Reference USA, an imprint of the Gale Group All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the Publisher. Macmillan Reference USA 1633 Broadway New York, NY 10019 Macmillan Reference USA Gale Group 27500 Drake Road Farmington Hills, MI 48331-3535 Gale Group and Design is a trademark used herein under license. Library of Congress Catalog in Publication Data Encyclopedia of public health / edited by Lester Breslow. p. cm. Includes bibliographical references and index. ISBN 0–02–865354–8 (set : hardcover : alk. paper) — ISBN 0–02–865350–5 (v. 1 : alk. paper) — ISBN 0–02–865351–3 (v. 2 : alk. paper) — ISBN 0–02– 865352-1 (v. 3 : alk. paper) — ISBN 0–02–865353–X (v. 4 : alk. paper) 1. Public health—Encyclopedias. I. Breslow, Lester. RA423 .E53 2001 362.l’03—dc21 2002031501 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 L LABOR UNIONS Act of 1970, greatly expanding the federal pres- ence in these areas. Unions have been the critical Labor unions are the major organizations pursu- force behind most major Occupational Safety and ing the collective interests of workers in the areas Health Administration (OSHA) standards, provid- of health and safety, especially in the mining, ing evidence in the rulemaking record and initiat- manufacturing, construction, health care, and trans- ing litigation to force rulemaking and to defend portation sectors. Beyond assisting members with rules against industry opposition. Exposure stan- their day-to-day needs through contract negotia- dards spearheaded by the union movement in- tion and administration, unions actively work for clude those for lead, formaldehyde, benzene, as- legislative and regulatory remedies for health and bestos, blood-borne pathogens, and coke-oven safety problems. Union influence extends far be- emissions. yond the workplaces of the 14 percent of workers In the second half of the twentieth century, in the United States who are unionized. Unions union and worker activity in occupational health bargain for specific improvements in working con- greatly expanded. The environmental movement ditions; representation and systems for improving of the 1960s led workers to be concerned about conditions, such as health and safety committees; the levels of chemical exposure in the workplace. and procedures for members to submit specific The black lung movement in the coal mines and complaints to abate hazards. They also provide the white lung movement based in cotton mills technical assistance, information, and training to spurred the enforcement of exposure limits to members facing chemical or safety dangers. Addi- chemicals and dusts. The emerging epidemic of tionally, traditional bargaining for hours of work, asbestos-caused cancer and lung disease defined medical benefits, disability insurance, and job se- an approach exposure control and compensation curity positively impact the health status of workers. of victims, including those in the general commu- nity. Limited rights of workers under the 1970 Unions work politically for the passage and OSHA law were expanded through collective bar- implementation of laws, standards, and regula- gaining, in part due to public recognition of work- tions designed to improve working conditions and ers’ rights to be fully informed of hazards and to worker health. Early twentieth-century legislation fully participate in their abatement. Unions cam- included wage and hour laws, limitations on child paigned for and then implemented information labor and industrial home work, workers’ compen- rules, such as chemical hazard communication sation, and state labor departments to inspect and community right-to-know, to facilitate the con- workplaces for hazards. The labor movement united trol of chemicals. with public health and public interest groups to pass the Federal Coal Mine Health and Safety Act Unions also defended research institutions of 1969 and the Occupational Safety and Health such as the National Institute of Occupational 669 LABORATORY PRACTICE STANDARDS AND GUIDELINES Safety and Health (NIOSH), bargained for joint Guidelines are also established regarding the in- research programs with employers, and partici- terpretation of quality control results and correc- pated in studies that identified many previously tions that need to be made if results are not unknown chemical hazards. Most recently, unions accurate. Additionally, practice standards for the helped expose underreporting of musculoskeletal laboratory may include safety procedures to be disorders, which spurred ergonomics programs followed and guidelines for actions to be taken and greatly extended the reach of the health and should laboratory accidents occur. In order to safety paradigm to light industry and the white– document that appropriate actions and proce- collar and service sectors. The expanding health dures have been followed within the laboratory, care sector was itself recognized as a high-risk standard practices should also include guidelines employer, particularly in the areas of infectious for the length of time that all records and docu- disease, chemical exposure, and ergonomic prob- mentation of corrective actions should be kept lems. The early twenty-first-century climate of cor- within the laboratory, and for computer back-up porate downsizing and off-shore production will procedures. challenge union-based and public occupational KATHLEEN L. MECKSTROTH health and safety institutions. FRANKLIN E. MIRER (SEE ALSO: Assurance of Laboratory Testing Quality; Diagnostic Testing for Communicable Disease; Labo- ratory Services; Laboratory Technician; Reference (SEE ALSO: Asbestos; Carpal Tunnel Syndrome, Laboratory) Cumulative Trauma; Mining; National Institute for Occupational Safety and Health; Occupational Disease; Occupational Lung Disease; Occupational LABORATORY SERVICES Safety and Health; Occupational Safety and Health Administration) Even though the role of pathogenic bacteria and viruses in human health was defined in the nine- teenth century, the first public health laboratories LABORATORY PRACTICE in the United States were called chemical laborato- STANDARDS AND GUIDELINES ries and only performed elementary analyses of milk, water, and other substances. The Minnesota Any laboratory that performs tests which aid in Board of Health established the first public health determining an appropriate treatment or action chemical laboratory in 1873, and in 1881 the New for an illness or disease must establish practice York legislature established the first state chemical standards and guidelines. Each laboratory proce- laboratory. By 1869, most of the larger cities in dure should include criteria for acceptable sam- Massachusetts had health boards that were actively ples or specimens; a list of equipment, supplies, involved in the area of sanitary engineering. The and reagents required; detailed step-by-step in- state’s public health laboratory, established in 1886, structions for the testing procedure itself; and a was intended primarily to perform chemical analy- list of the quality control procedures to be in- sis, though it was called a “hygienic” laboratory. cluded, the results to be reported, and the inter- Michigan followed Massachusetts’ lead, moving pretations of those results. Since some tests may into the regulation of food and water, and in 1887, require immediate action, protocol should also the Michigan State Laboratory of Hygiene was include directions on reporting details. Guide- established, with Dr. Victor C. Vaughn as director. lines for reporting results to government agencies Both the Massachusetts and Michigan state as required under local or state laws are also hygienic laboratories began working on the con- established. nection between the public water supply and ty- In order to protect individuals and sensitive phoid fever. This was probably the first application information, strict confidentiality guidelines should of bacteriology to sanitary science in the United be developed for reporting results. These confi- States. By 1890 a number of state and local labora- dentiality guidelines should include disciplinary tories were established, with many of them doing actions to be taken if protocols are not followed. both chemical and bacterial analysis. 670 LABORATORY SERVICES The nation’s first diagnostic public health labo- role of the department. However, this new health ratory was the result of work by Drs. Hermann M. department tool of diagnostic bacteriology was Biggs and T. Mitchell Prudden. In 1887, these two not readily accepted by the general medical pro- physicians were able to isolate Vibrio cholerae, the fession. Duffy, in “The Sanitarians,” quoted from bacterium that causes cholera, from the feces of ill an 1884 JAMA journal article on Robert Koch and passengers on an immigrant ship anchored in New the tuberculosis (TB) bacillus that concludes a York City harbor, and they were anxious to pro- “too ready acceptance of the bacillus doctrine” was mote their technique as a routine diagnostic meas- likely to do more harm than good and that “nei- ure. It was not until a cholera scare in 1892, ther phthisis nor any form of tuberculosis (was) however, that they were able to convince the city contagious.” health department of the need to establish a labo- Biggs and his associates in New York City met ratory to develop and use diagnostic methods. On strong resistance from physicians to the city’s board September 9 of that year, the New York City of health requirement to report all cases of tuber- Department of Health’s Division of Pathology, culosis. The attitude of New York physicians was Bacteriology, and Disinfection was created, with duplicated around the country as more and more Dr. Biggs as the director. health departments instituted this requirement. Biggs soon had a second disease upon which Through perseverance and laboratory expertise, to focus his attention. Cases of diphtheria peaked health departments were eventually able to con- in the 1890s in New York City, and Biggs was ready vince the public and physicians that tuberculosis with a bacteriological diagnostic technique. He was communicable and not an hereditary disease used this technique to demonstrate that half the related to environmental conditions. patients in the New York City diphtheria hospital As the diagnostic expertise of the laboratories had been misdiagnosed. Because of this high rate grew, the ability of the public health dpeartments of misdiagnosis, he stressed that laboratory testing to control disease was bolstered. The ability to to confirm a diagnosis would be cheaper than culture disease-causing organisms from asympto- disinfecting and quarantining the homes of every matic people led to recognition of the carrier state case of suspected diphtheria. The health board and a reexamination of isolation practice. Labora- agreed, and the first official medical bacteriologist tory-supported disease control efforts resulted in in the United States, Dr. William H. Park, was significant reductions in disease mortality by the appointed. Meanwhile, Biggs continued the ex- early twentieth century. pansion of the laboratory’s diagnostic capabilities. He began routine laboratory bacteriological test- By mid-century, most of the laboratories had ing on every suspected tuberculosis case, despite evolved in service provision to the same general his colleagues’ skepticism of its value. In 1895, scope provided today: testing support of the com- Biggs added vaccine production to the laboratory. municable disease programs, chemical and bacte- He and his assistant, Park, refined the methods for riologic testing of drinking water, analysis of food production of the smallpox vaccine, and of diph- and milk, and limited non-communicable disease theria and tetanus antitoxins. testing. As continuing advances in technology en- hanced the diagnostic capabilities of the laborato- The New York City public health laboratory ries, the public health department core functions became a model for other public health depart- of assessment, policy development, and assurance ments. Within a few years, the diagnostic public were significantly strengthened. health laboratory had become an essential compo- nent of an effective health department. Development of federal public health labora- tories was slower than at the state level, although the nucleus of what would evolve into the National HISTORICAL SCOPE Institutes of Health was established in 1887. In that The laboratory added a new dimension to public year Joseph Kinyoun founded the Laboratory of health department activities. The ability to isolate Hygiene, a bacteriology research laboratory at the and identify disease-producing organisms immeas- Marine Hospital on Staten Island. In 1891, this urably strengthened the prevention and control laboratory was moved to Washington, D.C., where 671 LABORATORY SERVICES it expanded into what became the National Insti- PHL support for assessment and assurance tutes of Health (NIH) forty years later. The NIH functions are the most diverse. Laboratory testing laboratories still focus primarily on research and to support assessment may involve specimens from are not usually considered front line public health people, animals, insects, fomites (inert vectors), laboratories. The Centers for Disease Control and and environmental sources. Examples of this type Prevention (CDC), which is the acknowledged apex of activity are varied, but one of the most common of the public health laboratory system, was estab- is to support the investigation of disease outbreaks. lished even later than the NIH. In 1942 the Office It is the laboratory’s role to isolate and identify the of Malaria Control in War Areas (MCWA) was causative agent and to identify the source of the established. In 1946 the MCWA was converted to infection, which may be other individuals, insect the Communicable Disease Center. It was renamed or animal vectors, water, food, or dirt. For exam- the Centers for Disease Control in 1980, and in ple, in a food poisoning incident associated with 1992 became the Centers for Disease Control and restaurant meals, the laboratory is pivotal in the Prevention. The CDC has since matured into a determination of whether the incident is localized collective group of laboratories and programs that (caused by poor food handling procedures or is dedicated to preserving the health and well- infected staff in a specific restaurant) or wide- being of the public. The testing performed by spread (caused by contaminated food distributed CDC, in conjunction with local and state laborato- to many places locally or nationally). ries, has been essential to the provision of safe Population surveillance studies for assessment drinking water, an increased awareness of the of disease prevalence in a community also rely on importance of environmental health issues, and testing and information provided by the PHL. the decline of communicable diseases such as syphilis. Neonatal screening for metabolic disorders, im- mune status screening, screening for sexually trans- mitted diseases, and screening for chronic dis- ROLE OF THE PUBLIC HEALTH eases are examples of this aspect of information LABORATORY gathering by PHLs. Initially, the role of the public health laboratory Rabies, botulism, and plague are examples of (PHL) was simply to serve any of the perceived rare but important diseases of public health sig- laboratory needs of the various jurisdictions. Over nificance that are not identified except in public time this role was defined more precisely, although health laboratories. Rabies is routinely identified still ambiguously, under general categories. The by dissecting out specific portions of the brain of PHL became a recognized central part of the suspect animals to look for the characteristic lesions public health infrastructure and was charged with produced by the rabies virus. Rabies testing may supporting this infrastructure in each of the three be performed as routine surveillance of the wild core public health functions—assessment, assur- animal population or as a necessary adjunct to ance, and policy development. Because PHLs dif- contact between an individual and a suspect ani- fer dramatically in complexity, dependent largely mal. Testing for Clostridium botulinum toxin (which on the population served, the test menus of the causes botulism) in food or humans requires, at laboratories differ greatly. In general, all laborato- present, the use of animals. This requirement is ries support the following core functions: testing the basis for the restriction of this assay to PHLs. information relevant to monitoring the environ- Plague surveillance is routinely done by PHLs in ment; assessing the population’s health status; areas where plague is endemic in the animal popu- investigating and controlling disease outbreaks; lation. If antibodies to plague are found in an treating and controlling communicable diseases animal population that may have contact with like tuberculosis, syphilis, gonorrhea, and chlamy- humans, such as ground squirrels near a picnic dia; acting as a reference laboratory for private area, the area is closed to the public until an sector laboratories; and assuring the safety of food eradication effort is successful. and water. In addition, many PHLs have ongoing applied research programs directed toward im- Support of the PHL for the assurance func- proving the reliability and efficiency of testing, tion of public health is probably the most unrecog- and identifying and controlling emerging problems. nized and underappreciated facet of its role. Some 672 LABORATORY SERVICES of the testing cited under the assessment func- In summation, the primary role of PHL is as a tion has elements of assurance, such as the con- service unit providing timely information to facili- firmatory reference testing that is offered to all tate the public health department’s mission to private laboratories without charge. Private sec- protect the health of the community. To ade- tor laboratories having difficulty identifying a quately perform this role, the laboratory must be microorganism—confirming the true antibody sta- functionally integrated within the health depart- tus of a patient or defining the resistance pattern ment’s relevant programs so that the needs and of Mycobacterium tuberculosis, for example—are able requirements of these programs are met. The to request help from a PHL. But the most impor- unbiased information and laboratory data pro- tant role of assurance testing is to assure that vided by a PHL are necessary adjuncts to an effec- community water supplies are safe to drink. In tive public health department. addition to testing drinking water for chemical and microbiological safety, recreational water is COST OF SERVICES tested to insure the safety of swimmers and bathers. Another assurance function, not readily ap- Health care funding continues to increase, but, parent to the public, is the screening of food according to Health and Human Services esti- handlers in restaurants and other facilities. Food mates, public health spending is only about 1 poisoning events trigger this function if an organ- percent of the total, and the expenditure for PHLs ism is suspected or identified that can be transmit- is only 3 percent to 5 percent of the public health ted through contamination of food by a food allocation. This demonstrates that federal, state, handler. The food facility staff is screened for and county governments are making a very cost- suspect pathogens by the PHL, and any individuals effective investment in PHLs. The cost savings of found to be infected are removed from the job population-based interventions based on PHL test- until subsequent testing assures that they no longer ing information is estimated to be analogous to are infected. the cost savings (ten dollars for every one dollar spent) of an effective immunization program. This The facet of assurance that is most often estimate is derived from potential medical costs thought of in connection with PHLs is the provi- saved versus screening costs for population-based sion of certain testing services to the indigent surveillance testing, including that done for ra- population and to other individuals who might not bies, lead poisoning, sexually transmitted diseases, otherwise be able to afford tests. This aspect of environmental carcinogens and pathogens, and PHL testing varies from state to state depending metabolic disorders in newborns. upon local laboratory resources or the availability of specimen transport to the state laboratory. LABORATORY STRUCTURE AND Participation of PHLs in the third core func- ORGANIZATION tion, policy development, is largely through con- sultation or regulatory services. PHL staff is in- Because of the wide variability in population be- volved in policy development that impacts research tween and within states, there is diversity in both and technology needs as well as health issues the structure and testing services of the PHLs in such as HIV/AIDS (human immunodeficiency vi- the individual states. All fifty states and the District rus/acquired immunodeficiency syndrome), sexu- of Columbia operate their own PHLs, and some ally transmitted diseases, and tuberculosis. Poli- states have local laboratories, which may be au- cies to solve environmental problems are often tonomous or simply local extensions of the state developed primarily by PHL staff. Some state PHLs PHL. The CDC functions primarily as a reference develop and implement regulations that govern laboratory for the state PHLs, providing confirma- all aspects of private clinical and local public labo- tory and esoteric testing services that the state ratory operations within the state. This includes laboratories do not have the resources to perform. laboratory personnel and facility licensure re- The CDC also funds assessment and assurance quirements and environmental monitoring studies at the local level to investigate issues of requirements. particular public health importance. The CDC is 673