{'fraction_non_alphanumeric': 0.013784461152882205, 'fraction_numerical': 0.0, 'mean_word_length': 5.947826086956522, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Review : Acetaldehyde and Formaldehyde: Is There a Cancer Risk for Man?

Acetaldehyde and particularly formaldehyde are genotoxic and when chroni cally inhaled by laboratory rodents can produce nasolaryngeal tumours, the distribution of which parallels the severity of irritation to the upper respira tory tract. The carcinogenicity of high concentrations of these compounds may result from a combination of weak tumour-initiating genotoxicity and tumour-promoting activity associated with mucosal cytotoxicity, irritation and hyperplasia. Epidemiological evidence is lacking for a cancer risk follow ing exposure to the low concentrations of these compounds present in ambient air, although laboratory evidence suggests that risk may be increased following chronic exposure to high concentrations.