Answer to Question #1:

Yes, for the following reasons:

• most workers reported symptoms soon after exposure in the new facility;
• the dust levels were very high (> 10mg/m³);
• the pattern of symptoms are consistent with exposure to organic dust.

Answer to Question #2:

Unlikely, for the following reasons:

• pattern of symptoms is not consistent with an allergy;
• no latency period present between exposure and symptoms (asthma, hypersensitivity pneumonitis).

Answer to Question #3:

• Skin prick test (or specific IgE) to the seed pollen;
• Confirm asthma using serial PEFR and lung function spirometry.

Answer to Question #4:

Organic dust toxic syndrome since symptoms occurred soon after exposure This could be confirmed by:

• Measuring endotoxin levels in air;
• Culturing the grass seed to assess possible contamination (bacteria/fungi);
• Could do a nasal/bronchoalveolar lavage on the patient (look for predominantly neutrophilic as opposed to eosinophilic inflammatory response).

Answer to Question #5:

Decrease exposure to the dust exposure levels:

• Enclose the sieving machine;
• Check and fix the ventilation system;
• Change work practices (decrease exposure time);
• Use of respirators (interim measure).