Particulate matter(PM) exposure has been shown to increase the morbidity and mobility of a variety of respiratory diseases, including COPD and asthma. This study focus on the effects of PM on the pulmonary function and acute exacerbation of COPD and asthma patients in China, where PM exposure is much heavier than the United States and European countries.

Particulate matter(PM) exposure has been shown to increase the morbidity and mobility of a variety of respiratory diseases, including COPD and asthma. This study focus on the effects of PM on the pulmonary function and acute exacerbation of COPD and asthma patients in China, where PM exposure is much heavier than the United States and European countries. This study is an observational study which lasts 3 years. Primary outcome measures:Change in spirometry (FEV1) of COPD, asthma patients and healthy volunteers in response to different exposure doses of PM.

Inclusion Criteria:

1. COPD patients: clinical manifestation of COPD; post bronchodilator FEV1/FVC<0.70.
2. Asthma patients: clinical manifestation of asthma; recurrent dyspnea; with or without wheezing; relief spontaneously or after using bronchodilators; FEV1/FVC<0.70,with positive bronchial reversible test.
3. Asthma combined with COPD (ACOS) patients: patients with ACOS are included in asthma group.
4. Healthy volunteers: No smoking history, or have quit smoking at least 5 years. Chest X-ray show no abnormality.
5. Information consent form should be signed before entering the study.

Exclusion Criteria:

1. The latest severe acute attack occurred within 4 weeks:

   1. Severe acute attack: status asthmaticus or acute exacerbation of COPD leading to consultation, emergency treatment，hospitalization, or glucocorticoid treatment（oral/i.v).
   2. Controllable non-hospitalized acute attack without glucocorticoid treatment(oral/i.v). COPD attack lasting less than 48h or asthma attack lasting less than 24h are not excluded.

2. Any history of acute/chronic respiratory diseases other than asthma and COPD, including lung cancer and pulmonary infection.

3. Plasma ALT or AST greater than 2 times of the upper normal limit; plasma Creatinine greater than 1.5 times of the upper normal limit.

4. Left heart insufficiency, or malignant arrhythmia.

5. HIV positive.

6. Acute cerebrovascular events within 3 months, including apoplexy, transient cerebral ischemia and acute coronary syndrome.

7. Uncured malignant tumors.

8. Addicted to drug or alcohol, or any history of psychiatric disorders.

9. Breastfeeding, pregnancy or planning to be pregnant.

10. Estimated lifetime less than 2 years due to underlying diseases.

Clinic-based population