Table 1.

Characteristics of the included studies.

Reference	N exposed/ reference	Workplace of exposed subjects	MnBa [µg/L] exposed/referenceb	MnInhc [mg/m3]
1. Bast-Pettersen et al. (2004)	100/100	Production of alloys, melting of ores, electric furnaces	10.40 ± 3.23/9.09 ± 2.62	0.30 (GM)d
2. Blond and Netterstrom (2007) and Blond et al. (2007)	92/19	Electro steel works, melting of scrap metal, manual and mechanical handling of Mn	10.08 ± 2.61/NA	NA
3. Lucchini et al. (1999)	61/87	Production of alloys, electric furnaces, crushing of ore, melting, casting	9.68 ± 3.20/6 ± 1.69	0.05 (GM)
4. Lucchini et al. (1997)	35/37	Production of alloys, electric furnaces, crushing of ore, melting	10.02 ± 3.11/6.93 ± 1.46	0.19 (GM)
5. Mergler et al. (1994)	110/145	Production of alloys, crushing and screening of raw materials and alloy products, casting, cooling of the product	10.97 ± 4.51/7.47 ± 2.53	0.23 (GM)
6. Sjögren et al. (1996)	12/39	Railway track company, welding, high alloy Mn steel	8.58 ± 2.27/7.08 ± 2.63	NA
7. Wang et al. (2006)	82/51	Vehicle manufactures	21.52 ± 23.24/13.30 ± 22.40	0.25 (AM)e
8. Yuan et al. (2006)	56/34	Machine works	48.50 ± 31.74/19.23 ± 12.32	0.14 (AM)

^aManganese in blood.

^bMeans ± SD.

^cInhalable manganese.

^dGeometric mean.

^eArithmetic mean.