*3.2. Citizen Science Footprint Results*

The EDC footprints for the 39 citizen scientists who participated in this study ranged from as low as 2.5 g to as high as 720.2 g, with high coefficients of variation (CV > 0.6) for the footprints across all household sizes (Table 4). Household cleaning products contributed nearly half of the total EDCs in the household-based citizen science study. Glass cleaners contain high concentrations of ethanolamines and glycol ether, while air fresheners contain high concentrations of fragrances [27]. Other products that often appeared on the top 10 lists for all 39 footprints were laundry detergent, carpet cleaner, sunscreen, bar soap, and shampoo (Figure 5). Laundry detergents, which generally contain high concentrations of ethanolamines and fragrances [27], are sold and used in larger quantities than are most of the other products.

**Table 4.** Summary by household size of endocrine-disrupting compound (EDC) footprint calculator results from 39 citizen scientists. Summary results include the average footprint per household size, standard deviation, coefficient of variation, and footprint ranges.


Evaluation of average masses provides an indication, for this study, of products that are used in most households. In contrast, products with very disparate median and mean values are used relatively in some houses and not at all in others. For example, relatively high values for both mean and median EDC masses from the citizen science portion of this study showed that laundry detergent, glass cleaner, and sunscreen contributed to many of the 39 EDC footprints obtained (Figure 6). In contrast, air freshener and carpet cleaner contributed substantially to the EDC footprints of some households but were not present at all in more than one-half of the households studied, as evidenced by much higher mean than median values for these compounds. Comparison of mean and median values can help future scientists identify potentially different sample populations with targeted outreach techniques. For example, it is likely that nearly all households will have some form of glass cleaner for windows and some laundry detergent. However, efforts to reduce contributions from air fresheners, carpet cleaners, furniture polish, dishwater detergent, and dryer sheets need to target communities where households are likely to have carpets, dishwashers, and dryers.

**Figure 5.** Average percentages of the contribution of each product to the overall footprint of cleaning products, health and beauty products, and laundry products, with products in the cleaning, health and beauty, and laundry categories, contributing an average of 44.9%, 34.8%, and 20.3%, respectively, to the total EDC footprints of the 39 participating citizen scientists. The size of each rectangle provides a visual representation of the extent to which that product contributes to the total footprint.

**Figure 6.** Average and median masses (mg) of EDCs calculated to be in each product for the 39 participating citizen scientists. Error bars represent the standard deviations.
