Evaluation of occupational exposure of workers from a portland cement industry in Uruguay

Introduction
Uruguay is a small country in South America that produces around 1.000.000 tons/year of portland cement in 5 plants of 3 companies. The cement produced is composed of calcium, silicium, aluminium, manganesium and ferrous oxides , sulphates and other materiales. When in contact with moisture in eyes or on skin, or when mixed with water, portland cement becomes highly caustic (pH>12) and will damage or burn the eyes or skin. Inhalation may cause irritation to the moist mucous membranes of the nose, throat and upper respiratory system or may cause or may aggravate certain lung diseases or conditions.

Methods
46 personal and zone airborne samples were collected in three plants and analyzed to determine occupational exposure. Samples of total and respirable dust were collected according to NIOSH methods 0500 and 0600. Powder X-ray difracction análisis was conducted using a Rigaku UltimaIV diffractometer operating Bragg-Brentano geometry to determine the crystalline phases present in some samples.The wavelength corresponds to the Cu-anode tube (λ=1.5418 Å).

Results
We found that in Plant 1: 50 % of the samples were above the TLV value and 25 % exceeded del action level. In Plant 2: 43 % > TLV and 21% > action level. In Plant 3: 38 % > TLV and 8 % > action level.

Discussion
2010 ACGIH TLV`S were considered as reference values being 1 mg/m3 for respirable Portland cement dust and 10 mg/m3 por total dust (PNOS). It was also considered 50 % of the TLV value as action level. We discuss the reasons we observed that could lead to this results and conclude that important measures should be taken to prevent occupational exposure including recommendations for the workers involved and the authorities of the industry.