Abstract Ca, CO, Ni, SO, P and Cr.

Abstract

            Welding is one of the fabrication
process for the joining of one or more similar and dissimilar metals as a
permanent joint with the application of heat and pressure. Welding should join
the metal by heat the metal to its boiling point, due to melting of metal
enormous amount of fumes should be evolved from this process. The welding fumes
should contain hazardous metal contaminates such as Al, Mn, CO2, Ca,
CO, Ni, SO, P and Cr. Expose of these welding fumes should produce health
effects and occupational diseases such as asthma, cancer, parkinson disease, neurotoxic effects,
hemoptysis and pulmonary functions disorder. It include the airborne contaminant monitoring of toxic gases
of weld bonding process on safety and health effects of welders. This study
should presents the standards of exposure of welding fumes and the safe
measures should be recommended.

 

Keywords: welding, welding fumes,
occupational disease, health effects.

 

1.0       Introduction

            Welding is a fabrication process to make high strength joint between
two or more parts by heating to their melting temperature, with or without the
application of pressure and with or without the use of filler metal. The filler
metal has a melting point approximately same as the base metal. A filler material is typically added to the joint
to form a pool of molten material that cools to form a joint that is usually
stronger than the base material.
Pressure may also be used in
conjunction with heat, or
by itself, to produce a weld. Welding also requires a form of shield to protect
the filler metals or melted metals from being contaminated or oxidized. There are  different
welding methods, including spot welding, metal inert gas (MIG), and tungsten
inert gas, which are forms of gas metal arc welding, arc welding, and gas welding.

 

Welding fumes

            Welding
fume are the airborne contaminates which are exhaled from the welding process.
These exhaled fumes should be generated due to heating of the metal to its
boilng 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 of
electrodes, coated flux, welding materials and the parent materials. Welding
gases are produced by the decomposition of fluxes or from the interaction of
ultraviolet light or high temperatures with gases or vapours in the air.

2.0       Methods

Air sampling

            Air
sampling is the process of collecting samples of air in order
to determine the concentration of contaminants in the air. It is used to
determine the contaminates in the work area or the ambient air. The
Occupational Safety and Health Administration (OSHA) requires monitoring to be
done using personal samples. Area sampling may provide information on
environmental exposure or background exposure. It should be expressed in mg/m3.

Personal air sampling

             Personal air sampling is used to determine the
specified worker’s exposure. This method personal air sampling device is fixed
at the collar of the worker which specifies the breathing zone. The breathing
zone is with in 30cm radius of mouth and nose. Personal samples ensure as far as possible that the air
sampled 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 and
exhaled. Spirometry is helpful in assessing breathing patterns that identify
conditions 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 manage
asthma.

·        
To detect respiratory disease in patients presenting with
symptoms of breathlessness, and to distinguish respiratory from cardiac disease as the cause.

·        
To measure bronchial responsiveness in patients suspected of
having asthma.

·        
To diagnose and differentiate between obstructive
lung disease and restrictive
lung disease.

 

3.0       Standards

·        
Ceiling limit

The exposure limit a worker’s exposure may never exceed.

·        
Sampling and analytical error

A statistical estimate of the uncertainty associated with a given
exposure measurement.

 

 

·        
Short-term exposure limit (STEL)

The average exposure to a contaminant to which a worker may be
exposed 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)

 They
are 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 American
Conference of Governmental Industrial Hygienists (ACGIH) and are published
annually by that organization. Like PELs, TLVs are also 8-hour, time-weighted
averages.

Exposure limit

·        
The ACGIH
has set an 8-hour TWA of 5 mg/m3 for
these welding fumes, measured as total particulate in the welder’s breathing
zone.

·        
OSHA
proposed an 8-hour TWA of 5 mg/m3 for
these fumes; this limit is established in the final rule.

(NOTE:
This limit applies to the total fume concentration generated during the welding
of iron, mild steel, or aluminum; the fumes generated by the welding of
stainless steel, cadmium, or lead-coated steel, or other metals such as copper,
nickel, or chrome)

Ø  The
occupational exposure limit recommended by NIOSH REL is 1mg/m3 (TWA) and 3
mg/m3(STEEL).

Ø  The
occupational exposure limit recommended by NIOSH IDLH is 500 mg/m3.

Ø  The
occupational exposure limit recommended by OSHA PEL is 5mg/m3(ceiling)

Ø  The
occupational exposure limit recommended by ACGIH TLV is 0.02mg/m3(TWA).

 

4.0       Conclusion

            This study should notify many
hazardous agents that could be exhaled from the welding process. Those fumes
had the contaminates of magnesium, manganese, chromium, copper, zinc, lead and
other metal oxides and metals fluorides. It shows that the exposure to these
fumes should be tends to acute and chronic diseases such as different types of
cancer and other pulmonary diseases. The welders should have associate with
reduction in health and affects QOL. This could be minimize by manufacturing
nano particles types of electrodes. The welding process could be handled in well
ventilated area, if space is confined use respirators. Welders should use
personal protective equipments such as nose mask, safety goggles with proper
shade number and local exhaust ventilation should be provided to remove the
fumes and gases in the welding area.