¶ … Local exhaust ventilation for the control of welding fumes in the construction industry -- a literature review" and this was published in the Annals of Occupational Hygiene. This paper notes that welding presents a challenge for industrial hygienists with respect to controlling exposure to fumes. The reason is that arc welders typically move from site to site, and these frequent changes in site make it difficult to set up ventilation systems or utilize other similar controls. Thus, the welders are exposed to fumes, because the nature of their work creates such fumes, in these environments where it is impractical to install ventilation systems. Some of the worst industries for this type of exposure are the construction and shipbuilding industries. The authors looked at the literature on this subject. In particular, they were interested in finding out if LEVs have proven to be a solution. Portable LEV systems are the most logical solution to this problem. The problem arises because fumes are created in the welding process, and these fumes such as those containing manganese or hexavalent chromium, or CO, or ozone, all contain exposure to hazardous fumes. LEV is the primary engineering control.

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The former involved controlled settings, but the latter reflected real world settings. They found four types of results. One is that portable systems are sometimes very simple, without filtration, and others contain HEPA filters. They also found that there were circumstances in which the position of the welder's body in relation to the plume made a difference in terms of their exposure; thus there are times when this can be a solution, but there are times when the welder needs to be in a more dangerous position. Alternately, where there is an LEV hood, the positioning on that hood is another way that the worker can control his/her level of exposure. This is important, because the paper highlights the different ways that the worker can ensure the highest level of protection to their own actions.
The authors concluded by noting that there is more to be done, in particular with hoods, in the field. Field studies highlight the challenges of real world conditions. Lab work is an important starting point, in particular to isolate variables, but the field work is where most of the learning will be done because it is difficult…