Abstract Welding is one of the fabricationprocess for the joining of one or more similar and dissimilar metals as apermanent joint with the application of heat and pressure. Welding should jointhe metal by heat the metal to its boiling point, due to melting of metalenormous amount of fumes should be evolved from this process. The welding fumesshould contain hazardous metal contaminates such as Al, Mn, CO2, Ca,CO, Ni, SO, P and Cr.
Expose of these welding fumes should produce healtheffects and occupational diseases such as asthma, cancer, parkinson disease, neurotoxic effects,hemoptysis and pulmonary functions disorder. It include the airborne contaminant monitoring of toxic gasesof weld bonding process on safety and health effects of welders. This studyshould presents the standards of exposure of welding fumes and the safemeasures should be recommended.
Keywords: welding, welding fumes,occupational disease, health effects. 1.0 Introduction Welding is a fabrication process to make high strength joint betweentwo or more parts by heating to their melting temperature, with or without theapplication of pressure and with or without the use of filler metal. The fillermetal has a melting point approximately same as the base metal. A filler material is typically added to the jointto form a pool of molten material that cools to form a joint that is usuallystronger than the base material.Pressure may also be used inconjunction with heat, orby itself, to produce a weld. Welding also requires a form of shield to protectthe filler metals or melted metals from being contaminated or oxidized.
There are differentwelding methods, including spot welding, metal inert gas (MIG), and tungsteninert gas, which are forms of gas metal arc welding, arc welding, and gas welding. Welding fumes Weldingfume are the airborne contaminates which are exhaled from the welding process.These exhaled fumes should be generated due to heating of the metal to itsboilng point and melting of the metals. These fumes are complex mixture of metallic oxides, silicates,fluorides and metal vapours. The welding fumes contains fine particles ofelectrodes, coated flux, welding materials and the parent materials. Weldinggases are produced by the decomposition of fluxes or from the interaction ofultraviolet light or high temperatures with gases or vapours in the air.2.
0 MethodsAir sampling Airsampling is the process of collecting samples of air in orderto determine the concentration of contaminants in the air. It is used todetermine the contaminates in the work area or the ambient air. TheOccupational Safety and Health Administration (OSHA) requires monitoring to bedone using personal samples. Area sampling may provide information onenvironmental exposure or background exposure. It should be expressed in mg/m3.Personal air sampling Personal air sampling is used to determine thespecified worker’s exposure.
This method personal air sampling device is fixedat the collar of the worker which specifies the breathing zone. The breathingzone is with in 30cm radius of mouth and nose. Personal samples ensure as far as possible that the airsampled best represents the air inhaled by the worker. Spirometric test· It is the most common of the pulmonary function tests (PFTs). It measures lungfunction, specifically the amount) of air that can be inhaled andexhaled.
Spirometry is helpful in assessing breathing patterns that identifyconditions such as asthma, pulmonary fibrosis, cystic fibrosis, and COPD. It is also helpful as part of a system of health surveillance, in which breathing patterns are measured over time. to diagnose or manageasthma.· To detect respiratory disease in patients presenting withsymptoms of breathlessness, and to distinguish respiratory from cardiac disease as the cause.
· To measure bronchial responsiveness in patients suspected ofhaving asthma.· To diagnose and differentiate between obstructivelung disease and restrictivelung disease. 3.
0 Standards· Ceiling limitThe exposure limit a worker’s exposure may never exceed.· Sampling and analytical errorA statistical estimate of the uncertainty associated with a givenexposure measurement. · Short-term exposure limit (STEL)The average exposure to a contaminant to which a worker may beexposed during a short time period (typically 15 – 30 minutes).· Time-weighted average (TWA)The average exposure to a contaminant over a given period of time,typically 8-hours. Permissible exposure limit (PEL) Theyare developed by the OSHA and are legally enforceable. PELs are 8-hour,time-weighted averages of airborne exposure.
Threshold limit value (TLV), It is the guidelines developed by the AmericanConference of Governmental Industrial Hygienists (ACGIH) and are publishedannually by that organization. Like PELs, TLVs are also 8-hour, time-weightedaverages.Exposure limit· The ACGIHhas set an 8-hour TWA of 5 mg/m3 forthese welding fumes, measured as total particulate in the welder’s breathingzone.· OSHAproposed an 8-hour TWA of 5 mg/m3 forthese fumes; this limit is established in the final rule. (NOTE:This limit applies to the total fume concentration generated during the weldingof iron, mild steel, or aluminum; the fumes generated by the welding ofstainless steel, cadmium, or lead-coated steel, or other metals such as copper,nickel, or chrome)Ø Theoccupational exposure limit recommended by NIOSH REL is 1mg/m3 (TWA) and 3mg/m3(STEEL).Ø Theoccupational exposure limit recommended by NIOSH IDLH is 500 mg/m3.Ø Theoccupational exposure limit recommended by OSHA PEL is 5mg/m3(ceiling)Ø Theoccupational exposure limit recommended by ACGIH TLV is 0.
02mg/m3(TWA). 4.0 Conclusion This study should notify manyhazardous agents that could be exhaled from the welding process. Those fumeshad the contaminates of magnesium, manganese, chromium, copper, zinc, lead andother metal oxides and metals fluorides.
It shows that the exposure to thesefumes should be tends to acute and chronic diseases such as different types ofcancer and other pulmonary diseases. The welders should have associate withreduction in health and affects QOL. This could be minimize by manufacturingnano particles types of electrodes. The welding process could be handled in wellventilated area, if space is confined use respirators. Welders should usepersonal protective equipments such as nose mask, safety goggles with propershade number and local exhaust ventilation should be provided to remove thefumes and gases in the welding area.