Table 4.

Health effects of PM in the immune system.

S. No.	PM type	Country/Location	Period	Patients/Subject	Health effects	Reference
1.	PM10 and PM2.5	Zhejiang and Shanxi, China	2012–2014	120 participants	Increased mtDNA copy number and IL-5 concentration	Wang et al. (2020a)
2.	PM10 and PM2.5	Italy	2014–2015	50 healthy adult volunteers	Impaired the immune system	Dolci et al. (2018)
3.	PM10 and PM2.5	Jinan, Shandong	2016	163 and 110 school children from the polluted and control areas, respectively	Decreased C3 and C4 levels, and B lymphocyte count	Li et al. (2019b)
4.	PM10	South Korea	2012–2013	100 participants	Impacts DNA methylation and immune responses	Lee et al. (2019)
5.	PM2.5	Mexico City	2013–2017	35 residents	Alters functional immune cell responses and increased risk for Tuberculosis development	Torres et al. (2019)
6.	PM2.5	Japan	2014–2015	Cell line study	Activated antigen presenting cells and T-cells led to respiratory diseases	Chowdhury et al. (2018)
7.	PM2.5	Shanghai, China	2016	43 volunteers	Saliva lysozyme (non-specific immune biomarker) was significantly inversely associated with indoor PM2.5	Gao et al. (2019a, b)
8.	PM2.5	United States	2012–2013	21 volunteers	Impairs critical antimycobacterial T cell immune functions	Ibironke et al. (2019)
9.	PM2.5	United States	2003–2011	774 participants	Impacts DNA methylation and the human immune system	Gao et al. (2019a, b)
10	PM2.5	252 Chinese cities	2013–2017	117,338,867 hospital admissions	Increased risk of diseases in the digestive, musculoskeletal, and genitourinary systems	Gu et al. (2020)