Influence of Indoor Air Filtration Strategies on Occupant Health Indicators

Feng Li

Status: Completed

Conditions: Risk Factors for Respiratory and Cardiovascular Disease

Treatments: Device: Central air handling unit air purification technologies

Study type: Interventional

Funder types: Other

Identifiers

NCT02769208

2014KY107

Details and patient eligibility

About

The purpose of this study is to evaluate whether two different central air purification technologies reduce air pollutant exposure and beneficially influence health as evaluated with a suite of biological markers related to cardiovascular and respiratory disease risk.

Full description

This study will test two common types of central air handling unit filtration technologies, high-efficiency particulate air (HEPA) filters and electrostatic precipitators (ESPs), to evaluate the impacts of these technologies on personal exposure to air pollutants and the associated cardiovascular and respiratory health outcomes. HEPA filters remove a high percentage of the particulate matter in the air, as do ESPs, but ESPs also generate ozone, which may have its own detrimental health effects. These air purification technologies will be placed in different combinations with a coarse pre-filter to protect the air exchange machinery (combinations: pre-filter only, pre-filter + HEPA, and pre-filter + HEPA + ESP) in both the residences and offices of study participants living on a factory campus in Changsha, Hunan Province, China. Large dormitories and office buildings with central air handling units are common in China and around the world, and so adding air purification into the central ducts represents a practical strategy to reducing personal exposure to air pollution and related health outcomes. The Changsha area commonly suffers from high air pollution, and the dormitories and offices on this workspace are already outfitted with both HEPA filters and ESPs. Therefore, testing these technologies in this environment presents a natural experimental condition to test the benefits of air purification. The study investigators hypothesize that both the pre-filter + HEPA and pre-filter + HEPA + ESP conditions will reduce particulate matter exposure and reduce biological markers of cardiovascular and respiratory disease compared to the pre-filter alone, but that the ESP will generate enough ozone to lead to lower health benefits than HEPA+pre-filter condition.

Enrollment: 89 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy adults;
• Live and work at the Broad Town work campus in eastern Changsha, Hunan Province, China

Exclusion criteria

• Has any of the following diseases: chronic respiratory, cardiovascular, liver, renal, hematological disease; diabetes mellitus;
• Has any other diseases that may confound or complicate the effects of the intervention
• Pregnant females

Trial design

Primary purpose: Prevention

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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89 participants in 2 patient groups

Group A: Pre-Filter Only Intervention

Active Comparator group

Description:

Subjects in Group A start with baseline conditions of pre-filter + HEPA + ESP in their offices and dorms. After a baseline biological measurement, they then receive a 5-week intervention in which both the HEPA and ESP are removed, leaving only a pre-filter. This intervention period includes a biological measurement 2 weeks into the intervention and other 4-5 weeks into the intervention. The baseline air purification conditions are then restored, and another biological measurement is taken 2 weeks after that.

Treatment:

Device: Central air handling unit air purification technologies

Group B: Pre-filter + HEPA Intervention

Active Comparator group

Description:

Subjects in Group B start with baseline conditions of pre-filter + HEPA + ESP in their offices and dorms. After a baseline biological measurement, they then receive a 5-week intervention in which the ESP is removed, leaving a pre-filter + HEPA combination. This intervention period includes a biological measurement 2 weeks into the intervention and other 4-5 weeks into the intervention. The baseline air purification conditions are then restored, and another biological measurement is taken 2 weeks after that.

Treatment:

Device: Central air handling unit air purification technologies