Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Metal Fume Fever


Related Terms

  • Brass Chills
  • Brass-Founder's Ague
  • Foundry Fever
  • Monday Fever
  • Smelter Chills
  • Welder's Ague
  • Zinc Chill

Differential Diagnosis

  • Acute bronchitis
  • Asthma
  • Organic dust toxicity syndrome
  • Polymer fever
  • Viral syndromes

Specialists

  • Medical Toxicologist
  • Pharmacologist
  • Preventive Medicine Specialist

Comorbid Conditions

  • Asthma
  • Chronic obstructive pulmonary disease (COPD)

Factors Influencing Duration

Absorbed dose is the primary determinant of severity of toxic effects and therefore the severity and duration of disability. Absorbed dose is dependent on environmental levels, routes of exposure (skin contact, inhalation, ingestion) and duration of exposure.
Other factors influencing disability include pre-existing disease, age, pregnancy, and allergy, all of which affect individual susceptibility to the toxic effect of chemical exposures. Psychological and emotional factors may also play a role in the extent and duration of disability.

Medical Codes

ICD-9-CM:
985.9 - Toxic Effect of Other Metals, That From All Sources Except Medicinal Substances, Unspecified Metal

Overview

Metal fume fever is an elusive industrial disease that has been known to exist for at least 170 years. It is seen primarily in welders who perform soldering, brazing, cutting, metalizing, forging, melting, and casting operations using elements of zinc, copper, iron, and other metals. Scrap metal cutters, brass foundry workers, brass solderers, molten metal fabricators, and steel alloy workers are also at risk for metal fume fever. Welders who smoke are at greater risk than those who do not. Zinc oxide fumes are proven to cause metal fume fever, although the syndrome may less commonly occur following exposure to metal oxide fumes from copper and magnesium. Currently, the arc welding of steel galvanized with zinc coating is the most common source of exposure.

Over the last several decades, the incidence of metal fume fever has been reduced considerably due to improved engineering controls and respiratory protection devices; however, significant occupational exposures to freshly formed metal oxide fumes still occur in the US and other countries.

Incidence and Prevalence: More than 1,000 cases of metal fume fever are reported each year in the US, which represents an underestimate of the actual number of cases (Baker 699). The underestimate is due to the resilient nature of the work population and the tendency for workers at risk to avoid seeking medical attention for their symptoms and to accept the transient discomfort associated with the syndrome. One study found that 31% of welders aged 20 to 59 had experienced metal fume fever (Baker 699). In 2002, there were 884 reported exposures due to metal fume fever (Watson 21).

Source: Medical Disability Advisor



Diagnosis

History: The clinical signs of metal fume fever typically appear within 4 to 12 hours after exposure. Workers tend to present in the later afternoon or early evening hours with a number of nonspecific complaints. They complain of a sweet or metallic taste in the mouth, as well as a distorted taste for foods and cigarettes. Fever, chills, sweating, nausea, headache, fatigue, chest and/or abdominal discomfort, muscle aches, and joint pains may also occur 8 to 12 hours after exposure.

Individuals also commonly complain of a constricted, dry, or irritated throat sensation that may give rise to hoarseness and coughing. The diagnosis of metal fume fever can be difficult, due to the nonspecific nature of the individual's complaints and the fact that the symptoms themselves resemble a number of other common illnesses. The diagnosis is based primarily on a history of exposure to metal oxide fumes.

Physical exam: Findings vary among individuals exposed and depend primarily upon the stage in the course of the syndrome during which evaluation occurs. Individuals can present with or without pulmonary findings of wheezing or crackles in the lungs upon examination with a stethoscope and associated shortness of breath. Individuals may have a fever of 100° F to 102° F (37.8° C to 38.9° C).

Tests: A complete blood count (CBC) may be done. An increased white blood cell count may develop 2-5 hours after exposure occurs. Blood may be drawn to check the level of oxygen in the blood (arterial blood gases or ABGs) but should be reserved for individuals with severe respiratory symptoms.

Pulmonary function testing may reveal a decrease in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in individuals who experience an asthma-like response to metal fumes. Chest x-ray findings are normally unremarkable. Urine and blood plasma zinc and other metal levels may also be elevated after exposure to zinc oxide and other metal fumes, but levels do not correlate well with severity of symptoms.

Source: Medical Disability Advisor



Treatment

Treatment of metal fume fever consists of symptomatic therapy, which includes removal from the exposure, bed rest, oral hydration, and medications to treat fever (such as aspirin or ibuprofen). Intravenous steroids may be required in severe cases, as well as inhaled bronchodilators for wheezing. Oxygen therapy for managing hypoxemia may be required.

Although removing the worker from the workplace setting in which exposure occurs is the most effective strategy for the prevention of metal fume fever, it is not a realistic long-term solution for either the worker or the employer.

Prevention of metal fume fever occurrence is paramount in the complete management of the disease. Prevention involves a number of direct interventional strategies in the workplace environment, the most important of which requires improved engineering controls. Increasing the general room ventilation, as well as installing permanent overhead exhaust hoods can reduce fume exposure concentrations. Portable exhaust collection systems can help remove metal oxide fumes generated by the welding process. In addition, fume extractors built into welding equipment are also extremely helpful engineering controls.

Personal protective equipment such as positive pressure air supply respirators and eye and skin protective gear should be used at all times when performing welding duties. The current 8-hour threshold limit value (TLV) of 5 mg/cubic meter and 15-minute short-term exposure limit (STEL) of 10 mg/cubic meter have been established to prevent adverse health effects secondary to exposure to zinc oxide fumes. However, various industry and case reports have indicated that metal fume fever symptoms can occur in individuals exposed to limits below the current TLV. The Occupational Safety and Health Administration (OSHA), the National Institute of Occupational Safety and Health (NIOSH), and the American Conference of Governmental Industrial Hygienists (ACGIH) have established TLVs, recommended exposure limits (REL), and permissible exposure limits (PEL) values to protect workers from exposure to hazardous levels of the metals and their oxides Therefore, instituting an aggressive prevention strategy is crucial in order to minimize adverse health effects in the occupational setting.

Prevention at the engineering control level and education of the workforce at risk have been shown to be instrumental in reducing the overall number of metal fume fever cases.

Source: Medical Disability Advisor



Prognosis

Complete recovery usually occurs within 12 to 24 hours of removal from the exposure, without any lasting effects. The next morning, the majority of the afflicted worker's symptoms are gone, appetite returns, and he or she is able to return to work, despite feeling slightly "hung over" from the experience of the previous 24 hours.

Symptoms often recur upon re-exposure. Prognosis is positive as long as the individual stays away from the offending agent.

Workers who have experienced previous episodes of zinc oxide or other metal fume exposure are also prone to repeat attacks of metal fume fever, particularly if they have not been exposed in the previous few days. Hence, the term "Monday fever," which refers to the development of tolerance after frequent repeated exposures, with loss of tolerance over the weekend exposure hiatus.

Source: Medical Disability Advisor



Rehabilitation

A physical therapy program to recover exercise capacity, endurance, and tolerance may be needed. Occupational therapy programs may be needed where metal fume fever repeatedly recurs.

Source: Medical Disability Advisor



Complications

Complications related to metal fume fever are unlikely.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

It is not necessary to restrict workers from returning to welding operations immediately after full recovery from an episode of metal fume fever, as long as engineering or personal protection controls have been implemented.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Has diagnosis of metal fume fever been confirmed?
  • Is there a history of the suspected metals exposure in the workplace?
  • Is the clinical illness, including the history, physical examination, and laboratory findings, consistent with other case descriptions?
  • Is the timing between exposure and clinical onset compatible with the known biologic facts about the hazard?
  • Does individual appear to develop tolerance after frequent repeated exposures, with loss of tolerance over the weekend exposure hiatus?
  • Does individual have an underlying condition that may affect recovery?

Regarding treatment:

  • If symptoms persist despite treatment, does diagnosis need to be revisited?
  • Are there special attributes of this particular individual that make it more or less likely that he or she would be so affected?
  • Are adequate preventive measures employed at the engineering control level?

Regarding prognosis:

  • Are adequate preventive measures in place?
  • Has individual recently worked in another organization where the suspected metals exposure is higher?
  • Are there additional lifestyle or behavioral factors that may potentially contribute to this condition?

Source: Medical Disability Advisor



References

Cited

Baker, Beth A. "Metal Fume Fever." Clinical Toxicology. Eds. Marsha D. Ford, et al. 1st ed. Philadelphia: W.B. Saunders, 2001. 699-703. MD Consult. Elsevier, Inc. 12 Nov. 2004 <http://home.mdconsult.com/das/book/42434392-2/view/1013?sid=278479449>.

Watson, William A., et al. "2002 Annual Report of the American Association of Poison Control Centers Toxic Exposure Surveillance System." American Journal of Emergency Medicine 21 5 (2003): 353-421. MD Consult. 1 Sep. 2003. Elsevier, Inc. 12 Nov. 2004 <http://home.mdconsult.com/das/journal/view/42434392-2/N/14092761?sid=278479448&source=MI>.

Source: Medical Disability Advisor






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