. Author manuscript; available in PMC: 2019 Jun 1.

Published in final edited form as: J Occup Environ Med. 2018 Jun;60(6):e312–e318. doi: 10.1097/JOM.0000000000001292

Table 5.

Maximum ordinal total hydrocarbon exposure levels and lung function among Deepwater Horizon disaster response and clean-up workers with 2 acceptable FEV₁ and FVC curves by pre-spill diagnosis of lung disease (n=6,288)

		No pre-spill diagnosis of lung disease (n=5,435)			Pre-spill diagnosis of lung disease (n=853)

Lung function	THc Level (ppm)	n(%)	Mean differences (95% CI)^*	p-value	n(%)	Mean differences (95% CI)^*	p-value
FEV₁, mL
	Level 1 (≤0.29)	783 (14.41)	Ref	Ref	130 (15.24)	Ref	Ref
	Level 2 (0.30–0.99)	2022 (37.20)	−3 (−49, 43)	0.91	312 (36.58)	−24 (−154, 105)	0.71
	Level 3 (1.00–2.99)	1816 (33.41)	44 (−4, 92)	0.07	297 (34.82)	−20 (−150, 111)	0.77
	Level 4 (≥3.00)	814 (14.98)	−15 (−71, 41)	0.60	114 (13.36)	−26 (−188, 135)	0.75
FVC, mL
	Level 1 (≤0.29)	783 (14.41)	Ref	Ref	130 (15.24)	Ref	Ref
	Level 2 (0.30–0.99)	2022 (37.20)	−4 (−58, 50)	0.88	312 (36.58)	34 (−113, 181)	0.65
	Level 3 (1.00–2.99)	1816 (33.41)	48 (−8, 104)	0.09	297 (34.82)	−13 (−161, 135)	0.87
	Level 4 (≥3.00)	814 (14.98)	21 (−44, 87)	0.52	114 (13.36)	−30 (−214, 154)	0.75
FEV₁/FVC%
	Level 1 (≤0.29)	783 (14.41)	Ref	Ref	130 (15.24)	Ref	Ref
	Level 2 (0.30–0.99)	2022 (37.20)	0.15 (−0.38, 0.68)	0.58	312 (36.58)	−1.30 (−2.95, 0.35)	0.12
	Level 3 (1.00–2.99)	1816 (33.41)	0.27 (−0.28, 0.83)	0.34	297 (34.82)	−0.29 (−1.96, 1.40)	0.73
	Level 4 (≥3.00)	814 (14.98)	−0.62 (−1.27, 0.03)	0.06	114 (13.36)	−0.25 (−2.31, 1.82)	0.81

Abbreviations: THc Level, maximum ordinal total hydrocarbon exposure level; ppm, parts per million; CI, confidence interval

Model adjusted for: age, height, height², weight, gender, ethnicity, race, pre-spill diabetes, education, employment, other oil industry experience, previous oil spill clean-up, residential proximity to Gulf Coast, smoking, secondhand smoke