Final answer:
American doctors might have been reluctant to admit the problem of industrial poisoning for American workers due to influence of corporations, financial and legal liabilities, and lack of awareness.
Step-by-step explanation:
American doctors might have been reluctant to admit that industrial poisoning was a problem for American workers due to various reasons. One reason could be the influence of powerful corporations that profited from industries causing the poisoning. These corporations might have used their influence to suppress information and discredit any claims of industrial poisoning. Additionally, admitting the problem could have led to financial and legal liabilities for both the companies and the doctors who may have been complicit. Lastly, there might have been a lack of awareness and understanding about the long-term health effects of exposure to toxic substances.