Question: when did the dangers of asbestos became known
[{'answer': '1899', 'provenance': [{'wikipedia_id': '21492663', 'title': 'Asbestos', 'start_paragraph_id': 19, 'start_character': 779, 'end_paragraph_id': 19, 'end_character': 783, 'bleu_score': 1.0, 'section': 'Section::::History.:Industrial era.\n'}]}, {'provenance': [{'wikipedia_id': '21492663', 'title': 'Asbestos', 'start_paragraph_id': 23, 'start_character': 0, 'end_paragraph_id': 23, 'end_character': 130, 'bleu_score': 0.807681595142239, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15243298980821728712}, 'section': 'Section::::History.:Discovery of toxicity.\n'}]}]