Ambient sulfur dioxide and hospital expenditures and length of hospital stay for respiratory diseases: A multicity study in China

• Dawei CaoShanxi Medical University
• Dashan ZhengSun Yat-sen University
• Zhengmin Min QianSaint Louis University
• Huiqing ShenShanxi Medical University
• Yi LiuShanxi Medical University
• Qiyong LiuChinese Center For Disease Control and Prevention
• Jimin SunZhejiang Center for Disease Control and Prevention
• Shiyu ZhangSun Yat-sen University
• Guangyuan JiaoCapital Medical University
• Xiaoran YangBeijing Municipal Health Commission
• Michael G. VaughnSaint Louis University
• Chongjian WangZhengzhou University
• Xinri ZhangShanxi Medical University
• Hualiang LinSun Yat-sen University