Table 1.

Concentration of PM2.5 and PM10 in Arequipa, Peru, during September and October 2019 (pre-COVID-19 pandemic period) and from May to October 2020 (COVID-19 pandemic period)

		September and October 2019 (pre-COVID-19 pandemic period)				From May to October 2020 (COVID-19 pandemic period)				ANOVA (p value)
		n	Mean	Max.	Min	n	Mean	Max.	Min
PM2.5 (μg m−3)	Full data set	45	52.15	82.87	26.90	151	48.43	94.41	18.36	0.1361
	Monday	7	49.07	58.78	38.00	21	48.99a	67.57	21.09
	Tuesday	7	51.79	66.90	45.12	20	51.86a	86.99	28.51
	Wednesday	6	53.91	82.87	38.44	23	50.94a	92.38	27.79
	Thursday	7	51.80	59.70	46.48	20	49.38a	65.71	35.44
	Friday	6	59.74	68.57	42.20	23	49.18a	68.43	29.32
	Saturday	6	51.46	72.49	38.75	23	53.35a	94.41	31.85
	Sunday	6	47.93	71.77	26.90	21	37.65b	68.71	18.36
ANOVA	(p value)		0.5899				0.0047
PM10 (μg m−3)	Full data set	45	79.10	125.45	45.43	151	75.36	154.92	26.66	0.2771
	Monday	7	76.40	87.72	58.21	21	72.79a	101.22	39.50
	Tuesday	7	79.87	106.25	69.00	20	81.69a	154.92	41.90
	Wednesday	6	85.20	125.45	62.57	23	78.88a	129.35	39.46
	Thursday	7	79.12	95.52	64.68	20	77.88a	103.11	55.43
	Friday	6	87.78	100.77	62.97	23	77.75a	107.89	46.32
	Saturday	6	75.37	111.21	57.96	23	82.24a	138.34	48.16
	Sunday	6	70.23	105.89	45.43	21	55.46b	99.97	26.66
ANOVA	(p value)		0.5435				0.0003

ANOVA between years and ANOVA among days of the week; different letters indicate statistical difference