The first content added was information on about 700 chemicals from the NIOSH Pocket Guide to Chemical Hazards. Using the yes/no fields in the Agents table, each chemical was flagged for the presence or absence of adverse effects as shown in the following table.
So, what are the most important adverse effects of chemicals in occupational toxicology? In Haz-Map, there is a distinction between adverse effects (includes animal toxicology and human poisonings by ingestion cases) and occupational diseases (cases of workers made ill after inhalation or skin absorption);
You can see a detailed list if you go to the Bibliography page on the Haz-Map website.
This world map was drawn by Flemish cartographer Abraham Ortelius in 1570. Today, satellites give us essentially complete knowledge of the earth’s surface so that you can zoom-in to see your house. In 1570, a map of the world was needed even though information was limited. Today, we can map the knowledge domain of occupational toxicology realizing that knowledge is incomplete and accuracy will increase as we learn more.
The need for knowledge mapping is great because there is so much information about occupational exposures and diseases.
Knowledge mapping that links occupational exposures to acute and chronic diseases can be useful for public health. Knowledge mapping begins with the big picture, and all of the information is kept in perspective. The need for knowledge mapping is great because there is so much information about occupational exposures and diseases; it is easy to get lost in the details.
The first attempt to draw the knowledge map of occupational toxicology was supported by NIOSH and published in a paper by Mullan and Murthy in 1991. 64 occupational diseases were linked to causal agents and associated industries, processes, or occupations; I started the Haz-Map project in the early 1990s when my goal was to put together a comprehensive list of occupational diseases and detailed toxicology information in a relational database.
Zooming in and out of a Google map is similar to zooming in and out of toxicology information. There is the big picture, and there are the details that fit into the context of the big picture. “Knowledge is information in context.”
*This is also referred to as the Agents table. Most records are toxic chemicals, but there are also biological agents in this table, e.g., natural latex rubber.
Haz-Map The number of records in each table gives you some idea of the amount of information in the database. The most time was spent on three tables: Chemicals, Diseases and Job Tasks. The Chemicals (or Agents) table is the largest table with 2801 records. “Agents” include chemical agents and also biological agents. Grain dust is an example of a biological agent.
Haz-Map The Chemicals table has 2800 records with each record having more than 50 fields. The fields are used to store information about the properties of the chemical, such as its vapor pressure (a number) and whether or not it is known to cause occupational asthma (yes or no). Because Haz-Map is a relational database, chemicals can be linked to industrial processes, for example, welding, and also to hobbies and other non-occupational activities explored in the occupational history. The bi-directional arrows mean that you can find all processes associated with lead or all chemicals associated with welding.
Haz-Map The diseases level of Haz-Map shows relationships between diseases and jobs or industries. The first step in building the content for the disease level of the database was to list and define the most important occupational diseases. Next, each disease was linked to one or more hazardous job task. In documented cases, what was the worker doing that caused the exposure to a sufficient dose that led to the disease? Finally, each job task was linked to the appropriate jobs and industries. In the following slides, we will first will look at some of the diseases in Haz-Map and then some of the job tasks that link the diseases to the jobs and industries.
Haz-Map In Haz-Map there are ten categories of occupational diseases. Airway diseases include occupational asthma, one of the most common occupational diseases. The pneumoconioses are the mineral dust diseases including asbestosis and coal workers pneumoconiosis. Farmers’ lung is an example of hypersensitivity pneumonitis. Hepatitis B from needle stick accidents is an occupational infection. There are 18 travel infections and 87 occupational infections in Haz-Map.
Haz-Map Chemical asphyxiation from carbon monoxide is an acute poison, and aplastic anemia from benzene is a chronic poison. Several important occupational diseases occur after daily exposures to metals, for example, lead poisoning. The most common skin diseases are irritant and allergic contact dermatitis. Lung, bladder and other cancers are associated with certain jobs and industries.
Haz-Map The next two slides show examples of the 224 hazardous job tasks in the database. Each job task is linked to one or more diseases and one or more jobs and industries.
This shows the first part of the profile on “Arsenic and compounds.”
Paging down on the profile for “Arsenic and compounds,” the user can see the occupational diseases to which this agent is linked.
This is the profile page for “Lung cancer,” one of 225 occupational diseases in Haz-Map.
The elephant is the knowledge domain of occupational toxicology. The blind scientists are the various sources of information. By putting together all of the limited perspectives, we get a better picture of the elephant.
So, we have a purpose here. We are not just collecting and storing every piece of information we can find.
Haz-Map Prevention is the goal. Occupational diseases can be prevented by interrupting the exposure pathway in the workplace. The worker can be removed from exposure by chemical protective clothing or by physically removing him/her from the job.
Haz-Map Prevention is dependent upon recognition. The number of occupational diseases reported is like the tip of an iceberg. Many occupational diseases are not recognized as such. A patient with occupational asthma has the same symptoms as any other patient with asthma. For asbestosis, there is a latency of at least ten years between exposure and disease. Medical students receive little training in the field of industrial toxicology. Finally, a large knowledge base is required to understand and diagnose work-related illnesses caused by chemicals and biological agents. So, there is a problem of under-recognition.
But we also have the tendency to assume that risks for occupational diseases are the same today as they were in the past. And so, there is also a problem of over-recognition.
US government regulations have had a huge impact on occupational & environmental exposures. These laws restricted the use of thousands of chemicals: ---Inside factories where workers are exposed; ---Outside factories where water and air pollution occur; Federal Insecticide, Fungicide & Rodenticide Act (FIFRA), 1948, 1972, 1975
The next five slides show the downward trend in exposures since the 1970s.
Symanski E, Kupper LL, Rappaport SM. Comprehensive evaluation of long term trends in occupational exposure: part 1. Description of the database. Occup Environ Med 1998;55:300-309.
Web site for AQMD , the air pollution control agency for the four-county region including Los Angeles.
Jensen AA, Breum NO, Bacher J, Lynge E. Occupational exposures to styrene in Denmark 1955-88. Am J Ind Med 1990;17(5):593-606.
Reference: PMID 9599454; Also see the update published in 2008 (PMID 18550430) in which the levels of PCBs and DDT dropped another 45% between 1999 and 2006.
With iteration, you get closer and closer to the desired result, which is the prevention of occupational diseases.
Getting it just right by balancing the weights of over-recognition and under-recognition;
The U.S. National Library of Medicine (NLM) is collaborating with the U.S. Department of Labor (DOL) to increase the number of chemical profiles in the database and to increase the frequency of updates to three times per year. The Haz-Map database, and particularly the links between causative agents and occupational diseases, supports the decisions of claims examiners for a DOL workers’ compensation program. To support sound decisions, the facts must be distilled from the vast sea of data in the scientific literature, much of it irrelevant for the questions at hand.
Haz Map: Linking Occupational Diseases to Causative Agents
LINKING OCCUPATIONAL DISEASES TO CAUSATIVE AGENTS A Collaborative Effort of the U.S. Department of Labor and the National Library of Medicine
PRESENTED BY JAY A. BROWN, MD, MPH CONSULTANT FOR THE U.S. DEPARTMENT OF LABOR AND THE NATIONAL LIBRARY OF MEDICINE Haz-Map Database: hazmap.nlm.nih.gov About Haz-Map: haz-map.com
Main Points <ul><li>Origin of the Database </li></ul><ul><li>Conceptual Framework of Haz-Map </li></ul><ul><li>Structure of Haz-Map </li></ul><ul><li>Screenshots of Haz-Map on the Web </li></ul><ul><li>Comparison to Other Toxicology Databases </li></ul><ul><li>Goal: Identify & Prevent Occupational Diseases </li></ul><ul><li>Iteration and the Scientific Method </li></ul><ul><li>Collaboration between the U.S. NLM and DOL </li></ul>
Question <ul><ul><li>Why can't we have a relational database of toxic chemicals and occupational diseases to store and query information similar to ones used by companies to manage data about employees, products, and customers? </li></ul></ul>
Chemicals Added to Database <ul><li>First content added: 700+ chemicals from the NIOSH Pocket Guide </li></ul><ul><li>Each chemical flagged for adverse effects </li></ul>
Controlled Vocabulary of Adverse Effects Category Adverse Effects Lung Toxin Asthma, Pneumonitis, Chronic Bronchitis, Fibrosis, and Cancer Neurotoxin Neuropathy, Parkinson's Syndrome, and CNS Solvent Syndrome Hematotoxin Methemoglobinemia, Aplastic Anemia, and Hemolytic Anemia Dermatotoxin Contact Dermatitis, Chloracne, and Skin Burns Carcinogen Known, Probable, or Possible Other Tissue Toxin Hepatotoxin, Nephrotoxin, and Reproductive Toxin Other Poison Organophosphate, Carbamate, Organochlorine, Uncoupler, Chemical Asphyxiant, and Simple Asphyxiant
Source of Information in Haz-Map: The Best and the Most Up-to-Date <ul><li>Journals and Monographs </li></ul><ul><li>Textbooks </li></ul><ul><li>CD-ROM Databases </li></ul><ul><li>Web Sites </li></ul>
According to a Report Released Today X Y Z Coffee Computer terminals Daycare Red wine Stress Fatty foods Exercise Smoking A feeling of well being Sexual dysfunction Depression Glaucoma Spontaneous remission Breast cancer Heart disease Hypothermia Men 25-40 Overweight smokers Rats 7 out of 10 women Arthritis sufferers Twins Children Two-income families
Knowledge Mapping <ul><li>“ Decision support systems can provide preliminary analysis that allows scarce human resources to focus on the key problems while ignoring a vast sea of irrelevancy.” [O’Carroll et al. 2003] </li></ul><ul><li>Knowledge is information in context. </li></ul><ul><li>Mapping means pulling together and sifting information from a lot of different sources. </li></ul><ul><li>Knowledge mapping is comprehensively collecting and systematically indexing a knowledge domain. </li></ul>
Knowledge Mapping <ul><li>Links occupational exposures to acute and chronic diseases </li></ul><ul><li>Begins with the big picture </li></ul><ul><li>Keeps all information in context of the whole </li></ul><ul><li>Distills the facts from the vast sea of data </li></ul><ul><li>Most useful in information-intensive specialties </li></ul><ul><li>Helps one not to get lost in the details </li></ul>
Drawing the Knowledge Map <ul><li>The Project by the National Institute for Occupational Safety and Health (NIOSH) </li></ul><ul><ul><li>Published list in 1991 </li></ul></ul><ul><ul><li>Occupational sentinel health events or SHE(O)s </li></ul></ul><ul><li>The Haz-Map project </li></ul><ul><ul><li>Expand the list </li></ul></ul><ul><ul><li>Add detailed toxicology information </li></ul></ul><ul><ul><li>Put in relational database </li></ul></ul>
High-Risk Job Tasks and Prevention <ul><li>Identify high risk groups </li></ul><ul><li>Not just presence of chemicals in the workplace that puts the worker at risk </li></ul><ul><li>But exposure AND absorption of sufficient dose </li></ul><ul><li>What is the specific job task that puts the worker at risk for the disease? </li></ul>
Examples of 224 Hazardous Job Tasks <ul><li>Manufacture polyurethane products </li></ul><ul><li>Remove insulation installed before 1975 </li></ul><ul><li>Extract coal </li></ul><ul><li>Inhale dust of moldy hay, silage, straw or grain </li></ul>
<ul><li>Handle medical needles or surgical instruments; </li></ul><ul><li>Operate internal combustion engine with inadequate ventilation; </li></ul><ul><li>Repair or maintain gasoline or jet fuel tanks; </li></ul><ul><li>Remove lead coatings; </li></ul>Examples of 224 Hazardous Job Tasks
Comparison of Haz-Map to Other Toxicology Databases <ul><li>ACGIH Documentation of TLVs and BEIs </li></ul><ul><li>NLM ChemIDplus and HSDB </li></ul><ul><li>NIOSH Pocket Guide and IDLH </li></ul><ul><li>ATSDR ToxProfiles and Case Studies </li></ul><ul><li>EPA CAMEO </li></ul><ul><li>CCOHS CHEMINFO </li></ul><ul><li>EXTOXNET </li></ul><ul><li>Emergency Response Guidebook </li></ul>
Pulling Information Together from Many Different Sources
Unique Features of Haz-Map <ul><li>First relational database of hazardous chemicals and occupational diseases; </li></ul><ul><li>Designed as a decision-support system to prevent occupational diseases; </li></ul><ul><li>Integrates the best information in toxicology, industrial hygiene, epidemiology, and occupational medicine; </li></ul><ul><li>Collects information from many sources to help users distinguish between significant and harmless exposures; </li></ul>
Occupational Diseases Are Preventable If the Causes Are Correctly Identified <ul><li>By removing the worker from exposure </li></ul><ul><li>By removing the exposure from the workplace </li></ul><ul><ul><li>Ban chemical </li></ul></ul><ul><ul><li>Enclose process </li></ul></ul><ul><ul><li>Establish exposure limit </li></ul></ul>
Why Occupational Diseases Are Difficult to Recognize <ul><li>Look like non-occupational diseases </li></ul><ul><li>Latency between exposure and disease </li></ul><ul><li>Inadequate training of medical students </li></ul><ul><li>Thousands of jobs, chemicals and diseases </li></ul>
Looking Through a Rearview Mirror “ . . . the profile of agents used in the industry has changed significantly over time, necessitating caution in applying the results of studies of health effects in prior decades, especially those evaluating carcinogenic risks of the industry, for currently exposed workers.” --- Steven Markowitz, p. 1025 “Synthetic Rubber Industry” in Textbook of Clinical Occupational and Environmental Medicine
US Environmental Laws 1969-1980 <ul><li>Federal Insecticide, Fungicide & Rodenticide Act; </li></ul><ul><li>National Environmental Policy Act (NEPA), 1969; </li></ul><ul><li>Federal Coal Mine Safety & Health Act , 1969; </li></ul><ul><li>Occupational Safety and Health Act (OSHA), 1970; </li></ul><ul><li>Clean Air Act (CAA), 1970; </li></ul><ul><li>Safe Drinking Water Act (SDWA), 1974, 1979; </li></ul><ul><li>Toxic Substances Control Act (TSCA), 1976; </li></ul><ul><li>Comprehensive Environmental Response, Compensation & Liability Act (CERCLA), 1980; </li></ul>
Hazardous Substances Banned in US, 1972-1991 <ul><li>All agricultural uses of DDT—1972; </li></ul><ul><li>Thallium rodenticides –1972; </li></ul><ul><li>Production of benzidine for commercial sale –1974; </li></ul><ul><li>Asbestos in insulation materials –1975; </li></ul><ul><li>Leaded gasoline in new vehicles –1975; </li></ul><ul><li>Production of PCBs –1977; </li></ul><ul><li>Sale of lead-based paint to consumers –1978; </li></ul><ul><li>Use of mercury in exterior paints –1991; </li></ul>
Just Right! <ul><li>The fine line between understating and overstating the risk </li></ul><ul><li>Drawing a map that is increasingly accurate with each iteration </li></ul><ul><li>Disseminating public health information that fits the current risk </li></ul>
Collaboration Between Agencies <ul><li>U.S. National Library of Medicine (NLM) and </li></ul><ul><li>U.S. Department of Labor (DOL) </li></ul><ul><li>To increase the number of chemical profiles </li></ul><ul><li>To increase the frequency of updates to three times per year </li></ul><ul><li>Uses the links between causative agents and occupational diseases to support the decisions of DOL claims examiners </li></ul><ul><li>Sound decisions supported by facts distilled from the vast sea of data in the scientific literature </li></ul>