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.
method is now widely used world-wild, ensuring the US and Canada to have constant gas supply for 100 years and has presented an opportunity to generate electricity at half the CO2 emissions of coal. (https://www.bbc.co.uk/news/uk-14432401) Steam-assisted gravity drainage (SAGD) is another method used to open up large deposits below the surface and produce heavy crude oil and bitumen. It is an advanced form of steam stimulation in which a pair of horizontal wells are drilled into the oil reservoir, one a few meters above the other. High-pressure steam is continuously injected into the upper wellbore to heat the oil and reduce its viscosity, causing the heated oil to drain into the lower wellbore, where it is pumped out. Similar to fracking, SAGD consumes large quantities of water and natural gas – 20 times more than conventional oil drilling, which makes it very expensive to operate. A possible alternative would be cyclic steam stimulation (CSS) and high-pressure cyclic steam stimulation (HPCSS). (https://en.wikipedia.org/wiki/Steam-assisted_gravity_drainage) Oil and gas in the Arctic Among the greatest uncertainties concerning future energy supply is the volume of oil and gas remaining to be found in high northern latitudes. According to the United States Geological Survey (USGS), there are about 30% of the world’s undiscovered gas and 13% of the world’s undiscovered oil may be found in the Arctic Circle. The recent retreat of polar ice makes petroleum exploration and development much easier. Petroleum is highly associated with sedimentary rocks. The map provided the basis for defining assessment units (AUs), which are mappable volumes of sedimentary rocks that share similar geological properties. The Circum-Arctic Resource Appraisal (CARA) defined 69 AUs, each containing more than 3 km of sedimentary strata, the probable minimum thickness necessary to bury source rocks sufficiently to generate significant oil and gas. (https://pubs.usgs.gov/fs/2008/3049/fs2008-3049.pdf) Figure. Map showing the AUs of the CARA is colour-coded for mean estimated undiscovered gas. Only areas north of the Arctic Circle are included in the estimates. Black lines indicate AU boundaries. Out of all 49 assessed AUs, CARA found that over 70% of the oil is concentrated in just 5 of them: Arctic Alaska, Amerasia Basin, East Greenland Rift Basins, East Barents Basins, and West Greenland-East Canada. Over 70% of the undiscovered gas is estimated to be in 3 provinces: the West Siberian Basin, the East Barents Basins and Arctic Alaska. The total mean undiscovered conventional oil and gas are estimated to be approximately 90 billion barrels of oil, 1,669 trillion cubic feet of natural gas, and 44 billion barrels of natural gas liquids.(https://pubs.usgs.gov/fs/2008/3049/fs2008-3049.pdf) This amount of resources is equivalent to 403.24 billion barrels of oil and would last for at least 13 years at current assumption rate. With such high concentration, it is easy to operate the mass production of petroleu>GET ANSWER