As scientific evidence evolves and clinical guidelines change, a certain amount of conflicting health information in the news media is to be expected. However, research is needed to better understand the public's level of exposure to conflicting health information and the possible consequences of such exposure. This study quantifies levels of public exposure to one paradigmatic case: conflicting information about breast cancer screening for women in their 40s. Using a nationally-representative survey of U.S. adults aged 18-59 in 2016, we implemented four distinct types of measures of exposure to conflicting mammography information: an ecological measure based on keyword counts of local news closed-captioning, an inferred exposure measure based on a series of knowledge questions, a thought-listing exercise where respondents described their perceptions of mammography without prompting, and an explicit measure of self-assessed exposure to conflict. We examined the relationship between these exposure measures and four outcomes: confusion about mammography, backlash toward mammography recommendations, and confusion and backlash about health information more generally. We found moderate amounts of exposure to conflicting information about mammography, more among women than men. Exposure to conflicting information - across multiple measures - was associated with more confusion about mammography, more mammography-related backlash, and general health information backlash, but not general confusion about health information. These observational findings corroborate experimental-based findings that suggest potentially undesirable effects of exposure to conflicting health information. More research is needed to better understand how to mitigate these possible outcomes, in the context of a media landscape that proliferates exposure to multiple scientific perspectives.