It is a prospective, multi-institutional clinical study and targets patients diagnosed with chronic obstructive pulmonary disease. About 120 subjects (35 at Ilsan Paik Hospital, 35 at Severance Hospital, and 50 at Asan Medical Center in Seoul) will be subject to a random allocation of 1:1. The arbitration group implements living rules for responding to fine dust, supports air purifiers, and only general guidance is implemented in the non-property group. Patients are recruited from Asan Medical Center in Seoul (Songpa-gu, Seoul), Severance Hospital ( Seodaemun-gu, Seoul), and Ilsan Paik Medical Center (Goyang, Gyeonggi-do) for 12 months. During outpatient visits, lung function tests and airway resistance tests shall be conducted, and surveys presented in the research plan shall be conducted.

It is a prospective and multi-institutional clinical study targeting patients with chronic obstructive pulmonary disease in general.

A total of 120 COPD patients will be recruited from three institutions: Asan Medical Center, Severance Hospital, and Ilsan Paik Hospital. (60/30/30 expected) A panel of COPD patients is established to conduct prospective studies, and measures to mediate recurrence and deterioration of adult chronic respiratory diseases due to exposure to fine dust are presented. Improvement of the lifestyle of the arbitration forces. Detailed research methods such as air purifier support are presented in the research plan.

In addition, a fine dust measurement researcher visits each household to measure indoor fine dust concentration. The measurement method of fine dust concentration will be using the process test method, IoT-based sensors, and direct-to-read measuring devices to measure Air Korea's air pollution. Detailed visit timing and methods are carried out in the manner specified in the research plan.

We collect sputum at every visit and blood at the last visit.

Inclusion Criteria:

• 40 years of age or older
• Waste function test results show FEV1/FVC<0.7, FEV1 <80% of forecast

Exclusion Criteria:

• Patients under 18 years of age with changes in medication (such as inhalants).
• Older people over 80 years of age.
• People with no respiratory symptoms with mMRC 0.
• Who doesn't understand a simple explanation for fine dust exposure devices.
• Someone who disagrees with the study.

The resident registration number may be used when requesting data from the National Statistical Office or the Health Review and Assessment Service for future research analysis and data collection.

Data are available at the time of the analysis of the results after the clinical study.

Gender, age, smoking power and address are collected anonymously.