Analysis of Aerosolized Particulates of Feedyards Located in the Southern High Plains of Texas

Figures & data

TABLE 1 PM₁₀ & PM_2.5 mean particulate filter data ^a of 4 feedyards (FY)

			Downwind			Upwind
	N	Site P value	N	Mean (μg/m^3)	SEM	N	Mean (μg/m^3)	SEM
PM10
FY1	32	0.001	15	362.19	59.83	17	89.95	19.93
FY2	32	0.001	16	363.19	85.11	16	88.35	37.97
FY3	32	0.05	16	275.01	54.69	16	144.05	51.85
FY5	32	0.07	16	80.90	14.39	16	51.27	8.06
PM2.5
FY1	32	0.001	16	30.13	3.36	16	17.95	1.70
FY2	32	0.002	16	33.51	7.28	16	15.33	4.38
FY3 ^b	32	0.65	16	24.58	4.44	16	28.44	8.47
FY5	32	0.05	16	12.18	1.20	16	8.60	0.93
			Summer			Winter
	N	Season P value	N	Mean(μg/m^3)	SEM	N	Mean (μg/m^3)	SEM
PM10
FY1	32	0.001	16	349.19	57.69	16	85.94	20.12
FY2	32	0.001	16	405.08	83.03	16	46.46	4.81
FY3	32	0.83	16	216.44	70.59	16	202.62	35.53
FY5	32	0.20	16	76.39	15.08	16	55.78	7.72
PM2.5
FY1	32	0.003	16	28.25	7.09	16	19.83	2.17
FY2	32	0.001	16	39.82	7.09	16	9.02	1.12
FY3 ^b	32	0.27	16	31.49	9.04	16	21.53	2.61
FY5	32	0.35	16	11.13	1.27	16	9.65	1.02

FIG. 1 PM₁₀ and PM_2.5 dust composite over days 1, 2, and 3 were analyzed by the Elzone method for mass and the geometric mean size are presented for FY1, FY2, and FY3 at the upwind and downwind positions. Note: The Elzone information for PM_2.5 from FY2 is missing due to insufficient amount of dust collected on the filters.

FIG. 2 PM₁₀ and PM_2.5 dust composite over days 1, 2, and 3 were analyzed by the Elzone method for population (count) and the geometric mean size are presented for FY1, FY2, and FY3 at the upwind and downwind positions. Note: see FIG. 1.

FIG. 3 Part A, is the Elzone (Coulter method) analysis of the feedyard particulates collected on filters by RAAS 300 PM_2.5 monitors in the summer, upwind and downwind of feedyard 1 and feedyard 3. Twenty-four hour filters for day 1, 2, and 3 were pooled in order to have adequate dust for the analysis. Data are presented in equal distant percentiles by quantity in μg/m³ ofair and mean size (μm in diameter). Part B, is the Elzone (Coulter method) analysis of the feedyard particulate collected on filters by RAAS 300 PM₁₀ monitors in the summer, upwind and downwind of feedyards 1, 2 and 3. Filters for day 1, 2, and 3 (are matched on the same days as Part A) were pooled in order to have adequate dust for the analysis. Data are presented in equal distant percentiles by quantity in μg/m³ of air and mean size (pm in diameter).

FIG. 4 Feedyard PM₁₀ Elzone analysis of parti culates on filters (day 1, 2, and 3 combined), percent of total particles and mean particle size by channel (0.77 sigma intervals) from upwind and downwind of three feedyards (FY1, FY2, and FY3).

FIG. 5 Feedyard PM_2.5 Elzone analysis of particulate on filters (days 1, 2, and 3 combined), mean (standard deviation [SD]) of total particles, and size data by percentiles (0,77 sigma intervals) from upwind and downwind of two feedyards.

FIG. 6 Scanning electron microscope graphic scan plot of a downwind PM_2.5 is filter from FY2. The particle is rich in Si and Al and appears to be a clay particle; note the amorphous shape.

TABLE 2 Scanning electron microscopy analysis of feedyards (FY) dust

Sample ID	Position	#Particles	0.35	0.75	1.75	3.75	7.50	15.00	> 20
Number percent distribution by average diameter (μm)
FY2PM2.5	Upwind	6946	23.72	33.86	40.43	1.82	0.17	0.00	0.00
FY2PM2.5	Downwind	4468	18.73	28.30	39.54	10.59	2.61	0.22	0.00
FY1PM10	Downwind	7767	17.09	18.23	30.34	22.64	10.74	0.96	0.00
Volume percent distribution by average diameter (μm)
FY2PM2.5	Upwind	6946	0.24	5.08	50.16	19.43	25.09	0.00	0.00
FY2PM2.5	Downwind	4468	0.04	0.68	10.05	25.39	38.16	25.68	0.00
FY1PM10	Downwind	7767	0.01	0.14	2.96	18.85	53.83	24.22	0.00

FIG. 7 Laser strategic aerosol monitor (SAM) data from four feedyards depicts channel mean total dust concentration ng/m³ ± standard error of mean (SEM) of air (9 channels) for each hour of the day which indicates a sharp rise in dust concentration at 1800 h, maximum at 2100 h, and a sharp decline at 2200 h.

FIG. 8 The general linear model (GLM) two-way interaction for the feedyard mean dust concentration (μg/m³) and mean particle size (μm in diameter) using laser strategic aerosol monitor (SAM) data.

TABLE 3 Comparison of mean non-respirable combined and respirable combined colony forming units (CFUs) from three data sets ^a (aerobic bacteria, Enterococcus spp and fungi)

Parameter	Pr > F value	Number of observations	Particle size Pr > F value	Non-respirable sample number	Non-respirable mean (± SEM)	Respirable sample number	Respirable mean (±SEM)
Summer	0.0001	384	0.0001	192	1370 (± 228)	192	390 (± 47)
Winter	0.0001	384	0.001	192	390 (± 47)	192	480 (± 59)
Downwind	0.0001	384	0.0001	192	1383 (± 223)	192	927 (± 132)
Upwind	0.00001	384	0.0001	192	376 (± 66)	192	425 (± 59)
FY1	0.0001	192	0.0001	96	1380 (± 370)	96	732 (±161)
FY2	0.0001	192	0.29	96	808 (± 191)	96	653 (± 145)
FY3	0.0001	192	0.56	96	781 (± 196)	96	726 (± 153)
FY5	0.0001	192	0.37	96	552 (± 114)	96	593 (± 129)
AM	0.0001	384	0.1001	192	980 (± 201)	192	645 (± 99)
PM	0.0001	384	0.42	192	780 (± 128)	192	707 (± 109)