Examining the role of wind in human illness due to pesticide drift in Washington state, 2000–2015

Table 9 Wind ramping characteristics during drift events with applicator records, AgWeatherNet (AWN) data, 2000–2015

Spray window	Length (hours)	Drift events (n)	Wind speed (mph)				Wind direction (degrees)			Both ramps^b
Spray window	Length (hours)	Drift events (n)	AM	SD	CV	Ramp events^a	SD	Range	Ramp events^a	Both ramps^b
Short	0.25–1.75	20	4.43	1.50	33.8	8	0.68	77.6	3	2
Medium	2.00–7.00	19	5.74	1.53	26.6	11	0.81	129.1	4	3
Long	7.25–15.75	18	4.78	1.79	37.5	13	1.16	232.0	9	7
Total	0.25–15.75	57	4.98	1.61	32.3	32	0.90	143.5	16	12

AM Arithmetic mean; SD Standard deviation; CV Coefficient of variation
a. A ramp event was defined as a drift event spray window with a wind speed or wind direction standard deviation greater than 1
b. Indicates the number of drift events that had both a wind speed ramp and a wind direction ramp

ISSN: 1476-069X