Acute health effects associated with satellite-determined cyanobacterial blooms in a drinking water source in Massachusetts

Table 4 The association between cyanobacteria concentration (maximum estimate based on five pixels) and the cases of gastrointestinal illnesses (sample size = 268); p represents the p-value

Lag (day)	Category of cyanobacteria cells^a	Regression coefficient	95% Confidence Interval		P
0	1	Reference
	2	0.54	−2.23	3.31	0.703
	3	1.55	−1.45	4.55	0.312
1	1	Reference
	2	−0.21	−3.01	2.59	0.883
	3	−2.24	−5.27	0.80	0.149
2	1	Reference
	2	−0.29	−3.04	2.46	0.837
	3	−1.30	−4.27	1.67	0.392
3	1	Reference
	2	−1.89	−4.68	0.90	0.185
	3	−0.44	−3.46	2.57	0.774
4	1	Reference
	2	−0.44	−3.23	2.34	0.755
	3	−1.70	−4.73	1.33	0.271
5	1	Reference
	2	−2.75	−5.63	0.13	0.062
	3	−1.58	−4.71	1.56	0.324

^aCategory 1: <=10,000 cell/mL; Category 2: above 10,000 cell/mL but below or equal to 109,468 cell/mL; and Category 3: > 109,468 cell/mL

ISSN: 1476-069X