Module 4: Organic Dusts - Exercise

The Netherlands is a major producer and exporter of agricultural seeds. Quality control of seeds is regulated by law and assigned to a specialized grass seed control institute. Routine procedures of seed control comprise the monitoring of microbial contamination; the viability (germination capability); and purity with regard to species and variety. Samples of approximately 0.5-1 kg are taken by producers or inspectors from batches of grass and other seeds. After the first steps in which general appearance and microbial contamination are recorded, the seed is cleaned by sieving, microscopically examined and tested by in-vitro culture to assess germination potency. In the cleaning room sieving is conducted with special machines equipped with shaking sieves of approximately 20 x 40 cm on which the seed samples are manually emptied. Above the sieves a hood is placed to remove dust. Each cleaning cycle takes a few hours, during which workers spend most of the time in the room, and often close to the machines.

In the last year the institute moved to a new building and all 7 workers were also relocated. Shortly thereafter workers in the cleaning room reported frequent episodes of respiratory and flu-like symptoms after work, which were suspected to be due to exposure to the dust and malfunctioning of the hood ventilation system. Dust measurements during work appeared to be relatively high on many occasions, often exceeding 10 mg/m³.

The following symptoms were reported by workers in the cleaning room during this period:

URT (stuffy nose, frequent nose bleeding) LRT (chest tightness, dyspnoea) Flu-like (fever, shivering) Joint pain GIT (diarrhoea, pain, nausea) Fatigue (chronic, recurrent) Headache, migraine

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