Respiratory symptoms and lung function in foundry workers using the hot box method: a 4-year follow-up

Area of Science:

• Occupational Medicine
• Environmental Health
• Pulmonology

Background:

• Foundry work involves exposure to hazardous chemicals, including monoisocyanates.
• Previous studies indicate potential respiratory and ocular effects from isocyanate exposure.
• The Hot Box method is a specific process used in foundries.

Purpose of the Study:

• To evaluate lung function and symptom prevalence in foundry workers exposed to monoisocyanates.
• To assess the impact of reduced exposure levels over a four-year follow-up period.
• To investigate persistent respiratory and ocular symptoms in this occupational group.

Main Methods:

• A longitudinal study design was employed, with assessments conducted four years apart.
• Participants included 25 foundry workers and 55 referents.
• Methods included spirometry (pre- and post-shift) and questionnaires on respiratory and ocular symptoms. Exposure levels of isocyanic acid, methyl isocyanate, and formaldehyde were quantified.

Main Results:

• Exposure levels to measured chemicals were reduced by 50% at follow-up.
• A high prevalence of nasal and ocular symptoms persisted in both exposed workers and referents.
• Lower airway symptoms decreased, but pre-shift lung function (forced expiratory volume in 1 second) was lower in the exposed group, with no significant change over the shift.

Conclusions:

• Persistent nasal symptoms and reduced pre-shift lung function in foundry workers suggest prolonged effects from past monoisocyanate exposure.
• Despite significant reductions in workplace exposure, the working environment may still influence long-term respiratory health.
• Further investigation into chronic effects and preventative strategies for foundry workers is warranted.