Question

Welding fumes are a common occupational exposure. Several different welding fumes can cause similar adverse health effects. Personal sampling of a welding operation at a manufacturing facility produced the following 8-hour time-weighted average (TWA) results for individual metal fumes.

Metal Fume	Result	OSHA PEL	ACGIH TLV
Antimony	0.05 mg/m³	0.5 mg/m³	0.5 mg/m³
Beryllium	0.00001 mg/m³	0.0002 mg/m³	0.00005 mg/m³ (I)
Cadmium	0.025 mg/m³	0.005 mg/m³	0.01 mg/m³
Chromium	0.02 mg/m³	1 mg/m³	0.5 mg/m³
Copper	0.03 mg/m³	0.1 mg/m³	0.2 mg/m³
Iron Oxide	0.5 mg/m³	10 mg/m³	5 mg/m³ (R)
Magnesium Oxide	0.02 mg/m³	15 mg/m³	10 mg/m³
Molybdenum	0.003 mg/m³	15 mg/m³	10 mg/m³ (I)
Nickel	0.25 mg/m³	1 mg/m³	1.5 mg/m³ (I)
Zinc Oxide	0.3 mg/m³	5 mg/m³	2 mg/m³ (R)

(R) Respirable fraction (I) Inhalable fraction

Briefly summarize the primary health effects associated with overexposure to each type of metal fume, including both acute and chronic health effects. Explain what analytical methods you would use for evaluating health hazards in the workplace.

Identify the types of metal fumes that would produce similar health effects on an exposed worker. Assume that each listed metal can cause respiratory irritation. Use the equation in 1910.1000(d)(2)(i) to calculate the equivalent exposure (in relation to OSHA PELS) for the metal fumes with similar health effects based on the “Result” column in the table above. Discuss whether you believe any of the individual metal fume exposures or the combined exposure exceeds an OSHA PEL or an ACGIH TLV.

Answer 1

Acute (short-term) exposure to antimony by inhalation in humans results in effects on the skin and eyes. Respiratory effects, such as inflammation of the lungs, chronic bronchitis, and chronic emphysema, are the primary effects noted from chronic (long-term) exposure to antimony in humans.

Acute effect of it produces severe cough, sore nose and throat, weight loss, labored breathing, anorexia, and increased fatigue.

Chronic effect of beryllium cause breathing difficulties (shortness of breath), coughing, fatigue, weight loss, fever, and night sweats. Signs include enlargement of the liver, spleen and right heart, and kidney stones.

Cadmium : Acute effect of cadmium cause fever and oral ingestion cause gastroenteritis.

Chronic effect of cadmium inhalation may result in impairment of pulmonary function with obstructive changes. Cadmium toxicity may cause renal dysfunction with both tubular and glomerular damage with resultant proteinuria. Bone changes appear to be secondary to renal tubular dysfunction.

Chromium :

Shortness of breath, coughing, and wheezing were reported from a case of acute exposure to chromium (VI), while perforations and ulcerations of the septum, bronchitis, decreased pulmonary function, pneumonia, and other respiratory effects have been noted from chronic exposure.
Copper :Acute symptoms of copper poisoning by ingestion include vomiting, hematemesis (vomiting of blood), hypotension (low blood pressure), melena (black "tarry" feces), coma, jaundice (yellowish pigmentation of the skin), and gastrointestinal distress.

Chronic (long-term) copper exposure can damage the liver and kidneys.

Iron oxide : Acute effect of exposue can cause metal fume fever. This is a flu-like illness with symptoms of metallic taste, fever and chills, aches, chest tightness and cough.

Prolonged or repeated contact can discolor the eyes, causing permanent Iron staining. Repeated exposure to Iron Oxide fume or dust can cause pneumoconiosis (Siderosis) with cough, shortness of breath and changes on chest x-ray.

Magnesium oxide : Exposure to Magnesium Oxide can cause “metal fume fever.” This is a flu-like illness with symptoms of metallic taste in the mouth, headache, fever and chills, aches, chest tightness and cough. The symptoms may be delayed for several hours after exposure and usually last for a day or two.

Chronic effect of its exposure can cause cancer.

Molybdenum : Exposure to Molybdenum can cause headache, fatigue, loss of appetite, and muscle and joint pain. Chronic exposure may raise the Uric Acid level in the body, which can lead to gout.

Zinc oxide :Acute effect is abdominal pain, nausea, and vomiting. Additional effectsinclude lethargy, anemia, and dizziness. Chronic effect is low copper status, altered iron function, reduced immune function, and reduced levels of high-density lipoproteins.

Nickel : Acute ingestion of nickel compounds may cause nausea, vomiting, diarrhoea, headache, cough and shortness of breath.

Chrnoic effect of nickel: Chronic bronchitis, reduced lung function, and cancer of the lung and nasal sinus.

Analytical methods of identification are :

1. Root cause analysis
2. Hazard and operating studies
3. Critical insident analysis
4. Event tree analysis
5. First order reliability method
6. Fault tree analysis

Beryllium, Cadmium, Chromium, Cobalt, Copper, IrOn and molybdenum can excede OSHA PEL