Table 1 Summary of ZIP code-level air pollution, meteorological covariates, and socioeconomic status (SES) covariates in the low pollution areas from 2000 through 2016

N (ZIP code)

4086

26,415

3708

N (beneficiaries)

7,988,816

63,639,732

12,992,320

          PM_2.5 (μg/m³)

5.2 (1.6)

9.6 (3.0)

7.8 (2.8)

          NO₂ (μg/m³)

23.2 (14.7)

27.6 (13.4)

29.7 (17.7)

          Warm-season O₃ (μg/m³)

88.8 (14.5)

88.2 (10.6)

73.1 (7.7)

          Summer average temperature (°C)

16.9 (4.0)

20.2 (3.7)

19.1 (5.1)

          Winter average temperature (°C)

3.1 (6.0)

6.2 (5.8)

7.5 (8.7)

          Summer average RH (%)

56.4 (14.7)

66.7 (9.4)

68.9 (7.1)

          Winter average RH (%)

66.3 (11.0)

66.9 (7.1)

70.0 (7.2)

          Percent Black (%)

1.1 (3.1)

8.5 (16.0)

6.5 (13.8)

          Percent Hispanic (%)

10.5 (16.7)

7.8 (14.4)

14.8 (22.2)

          Median household income ($)

46,759 (17,253)

48,419 (20,204)

52,232 (23,002)

          Median house value ($)

175,012 (133,349)

149,969 (124,583)

230,709 (191,296)

          Percent owner occupied (%)

75.8 (11.3)

74.2 (14.0)

69.1 (18.5)

          Percent education <high school (%)

22.0 (14.8)

28.1 (16.1)

24.4 (16.4)

          Population density (persons/mi²)

225 (751)

840 (2089)

3445 (10,150)

          Percent ≥65 below poverty (%)

9.4 (7.9)

10.1 (7.7)

10.3 (8.4)

          Percent annual HbA1c test (%)

82.0 (9.5)

83.5 (5.9)

84.6 (4.8)

          Percent ambulatory visit (%)

78.1 (7.4)

79.8 (6.0)

76.6 (7.2)

          Percent eye exam (%)

68.9 (7.7)

67.3 (6.7)

70.5 (6.3)

          Percent LDL test (%)

75.6 (10.7)

78.6 (7.3)

80.6 (5.5)

          Percent mammogram (%)

64.6 (9.0)

64.1 (7.2)

66.1 (7.3)

          Distance to nearest hospital (km)

18.2 (15.9)

12.2 (10.6)

10.2 (10.6)

          Lung cancer rate (‰)

0.4 (5.7)

0.4 (2.2)

0.4 (6.0)

          Ever smokers (%)

48.0 (7.7)

47.3 (7.4)

47.6 (7.7)

          Mean BMI (kg/m²)

28.1 (3.1)

28.1 (2.5)

27.4 (1.7)