Costs of Air Pollution in California’s San Joaquin Valley: A Societal Perspective of the Burden of Asthma on Emergency Departments and Inpatient Care

Figures & data

Table 1 Health Endpoints

Health Endpoint	ß -value	Source
ED visits, O3	1.003 per ppb	Zarate-Gonzalez et al (2024)^Citation28
ED visits, PM2.5	1.012 per µg/m3	Zarate-Gonzalez et al (2024)^Citation28
ED visits, NO2	1.023 per ppb	Zarate-Gonzalez et al (2024)^Citation28
Hospital visits, PM2.5	1.015 per µg/m3	Zarate-Gonzalez et al (2024)^Citation28
Hospital visits, NO2	1.028 per ppb	Zarate-Gonzalez et al (2024)^Citation28
Hospitalization length of service	Mean 6.3 days per event	Zarate-Gonzalez et al (2024)^Citation28
Use of controllers	Mean 4.84 per event	Kattan et al (2005)^Citation47
Use of rescue inhalers	Mean 5.95 per event	Kattan et al (2005)^Citation47
Cromolyn	Mean 2.64 per event	Kattan et al (2005)^Citation47
Use of antibiotics	0.31–0.58 per event	Kattan et al (2005)^Citation47
School absences	Mean 9.2	Moonie, Sterling, Figgs, and Castro (2006)^Citation48
Work loss days >18 - 64	0.122	CHIS (2021)^Citation49
Opportunity cost > 65	Mean 3.5	Van Der Zee et al (2000)^Citation50
Asthma prevalence in the SJV region 2–17	0.11	CHIS (2021)^Citation49
Asthma prevalence in the SJV region 18–64	0.196	CHIS (2021)^Citation49
Asthma prevalence in the SJV region > 65	0.175	CHIS (2021)^Citation52

Figure 1 Cost typology for Asthma & URI ED visits and Hospitalizations.

Table 2 Economic Values

Health Endpoint	US Dollar Value	Source
ED visits	427.91	CMS PFS (2016)^Citation58 procedures performed for ICD10 codes: J45, J06, R05-R06, Z77.1
Hospital visit	2099.55 per inpatient day	CMS Inpatient Data (2016)^Citation58 for hospitalizations with ICD10 codes: J45, J06, R05-R06 and Z77.1
Controllers	281	Epocrates (2023)^Citation68
Rescue inhalers	78	Epocrates (2023)^Citation68
Cromolyn	332	Epocrates (2023)^Citation68
Antibiotics	57–67	Epocrates (2023)^Citation68
School absences	60.23	Ed-Data Education Data Partnership (2016)^Citation70
Work loss days >18	80.43–137.33	California EDD (2023)^Citation69 and US Bureau of Labor Statistics (2018)^Citation71
Opportunity cost > 65	45.33	Social Security Administration (2017)^Citation72

Table 3 Attributable Risk Proportion

Exposure	IQR	OR	95% CI	AP	Lower/Upper Limit
O3 ED Visit	20.6	1.068	1.005–1.135	0.063	0.025–0.118
NO2 ED Visit	4.5	1.149	1.121–1.177	0.129	0.108–0.151
PM2.5 ED Visit	14.5	1.222	1.189–1.256	0.181	0.159–0.204
NO2 Hospitalization	4.5	1.157	1.083–1.236	0.135	0.076–0.191
PM2.5 Hospitalization	14.5	1.170	1.078–1.269	0.145	0.073–0.212

Table 4 SJV Region Population Attributable Fraction

Exposure (Background)	% of ED visits Pe	% of Hospital Admissions Pe	PAF (%)	95% Confidence Interval
O3 ED Visit	33.51	–	6.31	0.40–11.87
NO2 ED Visit	36.11	–	7.49	5.21–9.70
PM2.5 ED Visit	36.53	–	4.75	3.80–5.70
NO2 Hospitalization	–	36.52	8.39	2.09–14.28
PM2.5 Hospitalization	–	36.10	3.41	0.73–6.03

Table 5 SJV Population Exposed by County and Criteria Pollutant

	Population Exposed to Ozone		Population Exposed to PM2.5				Population Exposed to NO2
	ED %	Pe	ED % Pe		Hosp % Pe		ED % Pe		Hosp % Pe
County
Fresno	52.64	504,009	35.52	340,091	34.35	328,889	24.88	238,217	23.34	223,472
Kern	59.21	507,482	54.08	463,514	51.57	442,001	56.76	486,484	51.51	441,487
Madera	52.89	79,421	27.24	40,904	28.78	43,217	0.00	N/A	0.00	N/A
Merced	49.28	129,493	26.88	70,632	28.28	74,311	0.64	1,682	1.00	263
San Joaquin	11.19	80,254	29.78	213,579	29.44	211,141	41.07	294,550	42.36	303,802
Tulare	7.02	31,733	88.11	398,287	86.30	390,105	90.71	410,040	93.40	422,200
All SJV Residents		1,363,117		1,485,964		1,468,880		1,468,473		1,485,558

Table 6 Emergency Department Events Attributed to Pollutant Background Levels

Asthma Exacerbations & URIs in:	O3	NO2	PM2.5	Value in US$
	ED	ED	ED
Children 2–17	7,388	8,764	5,565	$ 108,650,057
	(470–13,897)	(6,103–11,361)	(4,449–6,669)
Adults 18–64	31,195	37,004	23,495	$ 336,980,497
	(1,982–58,675)	(25,768–47,971)	(18,787–28,157)
Adults 65+	5,315	6,305	4,003	$ 52,383,571
	(338–9,997)	(4,390–8,173)	(3,201–4,797)
SJV Population	43,895	52,069	33,061	$ 498,014,124
	(2,790–82,562)	(36,259–67,501)	(26,435–39,620)
Value in US$	$ 169,428,261	$ 200,978,032	$ 127,607,832

Table 7 Hospital Events Attributed to Pollutant Background Levels

Asthma Exacerbations & URIs in:	NO2	PM2.5	Value in US$
	Hospitalizations	Hospitalizations
Children 2–17	9,818	3,998	$ 41,769,155
	(2,442–16,719)	(850–7,060)
Adults 18–64	41,454	16,879	$ 156,102,152
	(10,311–70,594)	(3,589–29,809)
Adults 65+	7,063	2,876	$ 25,681,413
	(1,757–12,028)	(612–5,079)
SJV Population	58,331	23,751	$ 223,552,720
	(14,509–99,333)	(5,051–41,944)
Value in US$	$ 158,866,918	$ 64,685,803

Table 8 Health Effects per Marginal Reductions of Pollution Concentration

	O3		NO2		PM2.5
Reduction	−1 ppb		−1 ppb		−1 µg/m^3
	Outcomes	Cost Savings	Outcomes	Cost Savings	Outcomes	Cost Savings
ED Visits
Children	− 350	$ 1,750,679	− 2,007	$ 10,038,758	− 1,310	$ 6,554,972
Adults	− 1,477	$ 5,429,769	− 8,472	$ 31,135,423	− 5,532	$ 20,330,386
65+	− 252	$ 844,057	− 1,443	$ 4,839,997	− 943	$ 3,160,356
Total in US$		$ 8,024,505		$ 46,014,178		$ 30,045,714
Hospitalizations
Children			− 2,254	$ 6,813,868	− 999	$ 3,021,055
Adults			− 9,516	$ 25,465,188	− 4,219	$ 11,290,463
65+			− 1,621	$ 4,189,449	− 719	$ 1,857,470
Total in US$				$ 36,468,505		$ 16,168,988
Total ED visits and Hospitalizations		$ 8,024,505		$82,482,683		$ 46,664,702

Zarate-Gonzalez G, Cisneros R, Gharibi H, Brown P. Air pollution related adverse respiratory health outcomes in California’s San Joaquin Valley: evidence from 2016 linked emergency department and hospital records. Environ Res Heal. 2024;2(2):025003. doi:10.1088/2752-5309/ad268a

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