In 2006, the California Air Resources Board (CARB) and local air quality management districts implemented an Emissions Reduction Plan for Ports and Goods Movement.

In Phase I, our study results indicated that policies regulating goods movement achieved the desired outcomes in improving air quality for the State, particularly in the goods movement corridors where most disadvantaged communities live.

Background

Objectives/Methods

Conclusions

Figure 3. Model predictive margins of hospitalizations and ER visits

Modeled reductions in Hospitalizations and ER Visits by domain in Los Angeles and Alameda Counties

The overall percent of enrollees with hospitalizations and ER visits decreased from 34% to 31% from 2005 to 2010 for enrollees living in GMCs, reaching the prevailing rate of 30% as those living in NGMCs and CTRLS. The corresponding rates in NGCs and CTRLs decreased minimum across years and even increased for the beneficiaries living the CTRLs.

After controlling for individual-level age, sex, race/ethnicity, English speaking capacity, comorbidities (e.g. asthma, COPD, heart disease, diabetes or hypertension), we found that reductions in exposures to NO2 were associated with a decrease in hospitalizations for enrollees in both counties, as well as hospitalizations in Los Angeles, and ER visits in Alameda. The reductions were greater for those in GMCs than those in NGMCs and in CTRLs.

Phase II is a retrospective cohort study using six years of medical claims data (2004 to 2010) from adult California Medicaid fee-for-service (FFS) beneficiaries with chronic conditions residing in 10 California counties, specifically we will do the followings:

• create various pollution surfaces and assign exposures to Medicaid beneficiaries’ home addresses.

• investigate whether regulatory actions contributed to reductions in long-term and intermediate-term air pollution exposures, and

• examine whether reductions in ambient air pollution exposures have led to decreases of emergency room (ER) visits and hospitalizations among beneficiaries with chronic conditions, including asthma, cardiovascular disease (CVD), chronic obstructive pulmonary disease (COPD) and diabetes.

Results

The enrollees living in goods movement corridors (GMCs, locations within 500 m of truck-permitted freeways, ports, or railways) have experienced the greatest reductions in exposures comparing with those in non-goods movement corridors (NGMCs, locations within 500 m of truck-prohibited freeways or 300 m of a connecting roadway), and control areas (CTRLS, outside of these two corridors) between the 2003-2007 pre-policy and 2008-2012 post-policy years.

Measured reductions in pollutant exposures by domain in Los Angeles and Alameda Counties

Figure 1. Modeled Exposure Surfaces for Los Angeles and Alameda Counties

26.32

20.23 22.99

19.08 21.08

17.25

PRE POST PRE POST PRE POST

GMC NGMC CTRL

NO2

• The preliminary results add to empirical evidence that air pollution control actions benefit people with chronic conditions through pollution exposure reductions and health outcome improvements.

• Our investigation also contributes to scientific knowledge regarding how to assess the health effects of longer-term, large scale, and more complex regulatory actions.

• The study also provides a unique opportunity to show the adequacy of using routinely collected medical claims data for health effect studies.

Figure 2. Measured pollutant means of NO2 for pre- and post-policy periods