Evaluating Neighborhood-Level Differences in Hair Product Safety by Environmental Working Group Ratings among Retailers in Boston, Massachusetts

Background: Personal care products are a notable source of exposure to endocrine-disrupting chemicals (EDCs). Racial/ethnic differences in the use of hair products containing EDCs are reported, with women and children of color more commonly using hair products that are hormonally active and contain EDCs than other racial/ethnic groups. There is limited research examining the neighborhood-level social and economic factors that may contribute to these reported disparities. Objectives: We aimed to examine the safety of hair products across sociodemographically diverse neighborhoods in Boston, Massachusetts. Methods: Eight neighborhoods were identified based on indicators of race/ethnicity and socioeconomic status (SES). We randomly selected 50 stores and collected data on the hair products for sale and their corresponding Environmental Working Group (EWG) Skin Deep hazard score. The association between neighborhood and EWG hazard category (low, moderate, high) was examined using a multinomial logistic regression. Results: A total of 14,019 hair products were identified in the eight neighborhoods. When considering products with EWG hazard scores, Roxbury, a lower income community of color, and Mission Hill, a lower income community, were reported to have a higher percentage of high-hazard hair products in comparison with Beacon Hill [12.2% (163/1,332), 11.4% (65/571) vs. 7.9% (30/382), respectively]. Differences between the safety of hair products were observed, with Roxbury and Mission Hill reporting more than a 2-fold higher risk ratio (RR) of finding hair products with high vs. low EWG scores in comparison with that of Beacon Hill [RR for Roxbury: 2.3, 95% confidence interval (CI): 1.1, 4.6; RR for Mission Hill: 2.3, 95% CI: 1.0, 5.4]. Other neighborhoods were also observed to have an increased RR in comparison with Beacon Hill, however, with 95% CIs that extended beyond the null. Discussion: Retail stores in neighborhoods with a higher percentage of residents of color and lower SES were found to be more likely to sell products with high hazard scores than stores in a higher SES and predominately non-Hispanic White neighborhood. https://doi.org/10.1289/EHP10653


Table of Contents
Table S1.The neighborhood and residential characteristics for the 15 neighborhoods in Boston not selected based on racial/ethnic composition and percentage below the poverty line.The selection process used zip code-level data.The count and percentages presented are based on the approximate boundaries of each neighborhood based on census block group-the smallest spatial unit with socioeconomic data from the American Community Survey 2014-2018 5-year estimates.
Table S2.Store and hair product characteristics across the eight Boston, MA neighborhoods in the study area.While 50 stores were visited, only 46 were found to have hair products marketed to women and children.The hair product characteristics presented below reflect the 46 stores with hair products visited.
Table S3.Risk ratio and 95% confidence intervals of finding hair products sold in a pharmacy chain with branches nationwide with moderate and high Environmental Working Group (EWG) hazard scores versus hair products with low EWG hazard scores comparing each neighborhood to Beacon Hill.Table S4.Risk Ratio and 95% confidence intervals of finding rinse-off and leave-in hair products with moderate and high Environmental Working Group (EWG) hazard scores versus hair products with low EWG hazard scores comparing each neighborhood to Beacon Hill.Table S5.Risk ratio and 95% confidence intervals of finding hair products with moderate and high Environmental Working Group (EWG) hazard scores versus hair products with low EWG hazard scores comparing higher quintiles of price (2 nd through 5 th ) to the lowest quintile of price.
Table S6.Risk ratio and 95% confidence intervals of finding hair products with higher quintiles of price (2 nd through 5 th ) versus the lowest quintile of price comparing each neighborhood to Beacon Hill.Table S7.Risk ratio and 95% confidence intervals of finding hair products with higher quintiles of price (2 nd through 5 th ) versus the lowest quintile of price comparing each neighborhood to Beacon Hill stratified by product type.Table S1: The neighborhood and residential characteristics for the 15 neighborhoods in Boston not selected based on racial/ethnic composition and percentage below the poverty line.The selection process used zip code-level data.The count and percentages presented are based on the approximate boundaries of each neighborhood based on census block group-the smallest spatial unit with socioeconomic data from the American Community Survey 2014-2018 5-year estimates.,273.7 31,938.6 15,981.1 12,192.1 47,879.2 6,379.3 9,520.7 14,510.4 50,392 8,149.6 16,162 4,841.2 32,727.3 19,920.0Notes: Total population, neighborhood size (area in sq mi), population density, percentage below the poverty line, percentage of educational attainment, and percentage of each racial/ethnic group.While neighborhoods were selected using zip codes, the neighborhood and residential characteristics are presented using census block group-level data, the smallest administrative unit with available sociodemographic information.

Rinse-off
Leave 0.3 (0.1, 0.6) (n=115) Note: Risk ratio with 95% confidence intervals of finding hair products with higher quintiles of price (2 nd through 5 th ) versus the lowest quintile of price (1 st ) comparing each neighborhood to Beacon Hill stratified by product type (rinse-off and leave-in) estimated by multinomial logistic regression (rinse-off n=5,699 and leave-in n=4,693).Chinatown was excluded due to the large amount of missing EWG score data (neighborhood 2).RR, risk ratio; CI, confidence interval a Equal quintiles:1 st quintile: $0.49-$5.29, 2 nd quintile: $5.29-$6.99, 3 rd quintile: $6.99-8.99, 4 th quintile: $8.99-$11.99 5 th quintile: $11.99-$73.99 (n=2116 in 1 st -4 th quintile; n=2115 in 5 th quintile) b The first quintile of price ($0.49-$5.29)was the reference category c Beacon Hill, which is predominately non-Hispanic White and high SES, was the reference neighborhood d Each neighborhood was assigned a number from 1-8; neighborhood 2 represents Chinatown If there were fewer than 4 stores of a store type in a neighborhood, we included all stores in our analysis.For example, if only two grocery stores were identified in a neighborhood, both stores would be included.d A separate random selection was conducted for chains with multiple branches in the same neighborhood to ensure only one of each branch was included.

Figure S1 .
Figure S1.Flow chart of the store selection and visitation process detailing the inclusion and exclusions.

a
Count of stores by store type (department, grocery, pharmacy, beauty supply store) across the 8 neighborhoods b Count and percent of hair products by all 12 hair product types originally catalogued into our database c Count of hair products by EWG hazard score (0-2 low, 3-6 moderate, 7-10 high) d Hazard scores of greater than or equal to 7 are classified as high hazard e Hair product type categories used in the secondary analyses f Count of hair products with missing prices by neighborhood Table

Table S2 :
Racial/ethnic categories based on the 2010 Census g Based on census block group-level data, North End was identified as the neighborhood with the highest percentage of non-Hispanic White residents Store and hair product characteristics across the eight Boston, MA neighborhoods in the study area.While 50 stores were visited, only 46 were found to have hair products marketed to women and children.The hair product characteristics presented below reflect the 46 stores with hair products visited.Count of stores by store type, count and % of hair product types, count of hair products by EWG score, mean EWG hazard score, % of hair products with high hazard score, median price, mean price by product type, and count of missing price data cBased on the census block group-level data, Fenway and South Boston Waterfront were identified as neighborhoods with the highest and lowest percentage below the poverty line d Associate's and/or Bachelor's degree e Master's, Professional school, and/or Doctorate degree f

Table S4 :
Risk Ratio and 95% confidence intervals of finding rinse-off and leave-in hair products with moderate and high Environmental Working Group (EWG) hazard scores versus hair products with low EWG hazard scores comparing each neighborhood to Beacon Hill.

Table S5 :
Risk ratio and 95% confidence intervals of finding hair products with moderate and high Environmental Working Group (EWG) hazard scores versus hair products with low EWG hazard scores comparing higher quintiles of price (2 nd through 5 th ) to the lowest quintile of price.