The objective of this survey is to identify factories and to recruit workers handling nanomaterials in order to conduct epidemiological study of the health hazards of workers potentially exposed to engineered nanoparticles in the nanotechnology industry. Two phases of survey were conducted in this study. Phase one survey was to identify the factories handling nanomaterials currently by telephone interview or mail questionnaire. If the answer was positive, we requested site visit to confirm the nanomaterials handling in this factory. In the phase two, we visited the factories and interviewed the production manager or hygienist by a detailed, structured industrial hygiene questionnaire. During the site visits, medical surveillance and exposure assessment of workers handling nanomaterials were requested.
We estimated that about 70 factories were manufacturing or using nanomaterials in Taiwan. Among the 70 nanotechnology factories, 39 factories were allowed us to visit and filled in detailed industrial hygiene information. There were 13 factories agreed to participate in medical surveillance and exposure assessment study. This survey described the industrial hygiene information of these 39 factories and some physic-chemical properties and use condition of nanomaterials handled in these 13 factories.
The size of nanotechnology factories in Taiwan was small. The number of employees ranged from 1 to 50. The total number of nanomaterials handling workers was estimated to be about 1000 workers in Taiwan. Among 39 nanomaterials handling factories, 6 manufactured nanomaterials only, 18 used nanomaterials only, and 15 both manufactured and used nanomaterials. Among the 21 nanomaterials manufacturing factories, most of them used wet process. Only 2 of them used dry process to manufacture nanomaterials. Most of the factories used local ventilation (54%) to control the emission of dust. Few of them used enclosed system or negative pressure environment to control dust emission. Among 39 factories visited, 25 of them (64%) were confirmed to handle nanomaterials less than 100 nm.
The 13 factories agreed to participate in medical surveillance included photocatalyst, nanomaterials, toilet, air cleaner, light emission device, nanopaint, colorants, carbon nanotube, textile, and self-cleaning tiles manufacturing factories. Most of size of handled nanomaterials were less than 100 nm. The duration and frequency of handling nanomaterials was short and low. The physical state of nanomaterials handled was frequently liquid solution, or powder combined with liquid solutions. Only one factory was handling carbon nanotube powder.
This survey provided the industrial hygiene information and some physic-chemical properties of nanomaterials handled in Taiwan nanotechnology industry factories. These information will assist hygienists to assess nanomaterials exposure and assist epidemiologists to assess health hazards of workers.