Formaldehyde and the nasal mucosa

Exposure to organic solvents and neuropsychological dysfunction: a study on monozygotic twins

Twenty one monozygotic twins exposed to organic solvents were compared with their non-exposed cotwins by performance in psychological tests. A further 28 monozygotic twin pairs were examined as a reference group. The study used 11 tests, 10 of which had shown an effect in previous studies on the results of exposure to solvents. Paired comparisons of the test scores showed the exposed twins to have lower performance in associative learning, digit span, and block design. These results agree with two previous studies that used a similar set of tests. Contrary to some other studies, psychomotor speed was not affected, but the results indicated a marginal effect on the control of hand movements. Further comparison of subgroups with a low and a high exposure showed the prevalence of subtle neuropsychological dysfunction to be greater among the more exposed twins.

Occupational exposure to formaldehyde and histopathological changes in the nasal mucosa

To study the cytotoxic effect of formaldehyde on the human nasal mucosa 75 men with occupational exposure to formaldehyde or to formaldehyde and wood dust, were examined, looking particularly at early signs of irritative effects and histopathological changes in the nasal mucosa. All men underwent a medical examination and a nasal biopsy specimen was examined by a pathologist and graded from 0-8 according to the morphological changes. A high frequency of nasal symptoms, mostly a running nose and crusting, was related to exposure to formaldehyde. Only three men had a normal mucosa; the remainder had loss of cilia and goblet cell hyperplasia (11%) and squamous metaplasia (78%); in six cases (8%) there was a mild dysplasia. The histological grading showed a significantly higher score when compared with unexposed contents (2.9 v 1.8). There was no dose response relation, no malignancies, and no difference in the histological score between those exposed to formaldehyde or to formaldehyde and wood dust.