Correlative Measurement of Four Biological Contaminants on Cotton Lint, and Their Implications for Occupational Health

Abstract

Four biological contaminants of cotton fibers (gramnegative bacterial cells, endotoxin, fungal cells, and (1-3)-(3-D-glucan)were measured in 13 cotton lint samples from international origins, using traditional microbio-logical spread plating and adaptation of the Limulus amoebocyte lysate (LAL) assay. Correlations were evaluated using Spearman's rank correlation analyses. Contamination levels ranged from 713 ± 212 to 216,830 ± 30,413 CFU/g gram-negative bacteria; 281 ± 29 to 9,250 ± 820 CFU/g fungal cells; 8.30 ± 0.89 to 137.89 ± 21.55 ng/g endotoxin; and 15.96 ± 5.18 to 2,964.42 ± 313.90 LAL-reactive units/g glucan. Positive correlations existed between all contaminants; however, they were significant only between fungal cells and glucan (P < 0.05) and between endotoxin and glucan (P < 0.01). The highly significant positive correlation between endotoxin and glucan has implications for the health risk posed by the cotton-production environment, as simultaneous inhalation of these agents may cause or exacerbate lung inflammation.

Keywords:

• beta-glucans
• byssinosis
• cotton fiber
• endotoxins
• fungal count
• gram-negative bacteria