Paternal Occupational Exposure to Endocrine-Disrupting Chemicals as a Risk Factor for Leukaemia in Children: A Case-Control Study from the North of England

Table 1

Number of cases and controls by disease group and likely level of paternal occupational exposure to endocrine disrupting chemicals.

	Level of exposure
	Polychlorinated organic compounds			Phthalates			Alkylphenolic compounds
	Very unlikely	Possibly	Likely	Very unlikely	Possibly	Likely	Very unlikely	Possibly	Likely
	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)
All leukaemia	635 (85)	37 (5)	78 (10)	587 (78)	32 (4)	131 (17)	580 (77)	60 (8)	110 (15)
Registry controls	26177 (87)	1222 (4)	2793 (9)	24265 (80)	1433 (5)	4494 (15)	22722 (75)	2683 (9)	4787 (16)
CBD controls	61652 (87)	3511 (5)	5836 (8)	54524 (77)	4979 (7)	11496 (16)	52291 (74)	6622 (9)	12086 (17)
Lymphoid leukaemia	531 (85)	32 (5)	61 (10)	496 (79)	29 (5)	99 (16)	492 (79)	51 (8)	81 (13)
Registry controls	21787 (87)	1014 (4)	2323 (9)	20197 (80)	1181 (5)	3746 (15)	18909 (75)	2196 (9)	4019 (16)
CBD controls	51558 (87)	2934 (5)	4908 (8)	45644 (77)	4188 (7)	9568 (16)	43832 (74)	5535 (9)	10033 (17)
Acute nonlymphocytic leukaemia	82 (81)	5 (5)	14 (14)	75 (74)	3 (3)	23 (23)	73 (72)	9 (9)	19 (19)
Registry controls	3603 (87)	165 (4)	389 (9)	3333 (80)	208 (5)	616 (15)	3135 (75)	400 (10)	622 (15)
CBD controls	8035 (87)	451 (5)	713 (8)	7056 (77)	630 (7)	1513 (16)	6725 (73)	851 (9)	1623 (18)
	Level of exposure
	Biphenolic compounds			Heavy metals			Other
	Very unlikely	Possibly	Likely	Very unlikely	Possibly	Likely	Very unlikely	Possibly	Likely
	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)	𝑁 (%)
All leukaemia	655 (87)	54 (7)	41 (6)	685 (91)	43 (6)	22 (3)	718 (96)	21 (3)	11 (1)
Registry controls	27004 (89)	1467 (5)	1721 (6)	27187 (90)	1730 (6)	1275 (4)	28977 (96)	730 (2)	485 (2)
CBD controls	63275 (89)	4168 (6)	3556 (5)	65683 (93)	3051 (4)	2265 (3)	65152 (92)	2560 (4)	3287 (5)
Lymphoid leukaemia	550 (88)	43 (7)	31 (5)	575 (92)	30 (5)	19 (3)	600 (96)	17 (3)	7 (1)
Registry controls	22459 (89)	1214 (83)	1451 (6)	22606 (90)	1460 (6)	1058 (4)	24095 (96)	620 (2)	409 (2)
CBD controls	52912 (89)	3488 (6)	3000 (5)	54958 (93)	2549 (4)	1893 (3)	54585 (92)	2109 (4)	2706 (5)
Acute nonlymphocytic leukaemia	87 (86)	7 (7)	7 (7)	92 (91)	7 (7)	2 (2)	96 (95)	3 (3)	2 (2)
Registry controls	3736 (90)	203 (5)	218 (95)	3743 (90)	223 (5)	191 (5)	4008 (96)	84 (2)	65 (2)
CBD controls	8258 (90)	523 (6)	418 (5)	8501 (92)	398 (4)	300 (3)	8371 (91)	356 (4)	472 (5)

Note. CBDC: Cumbrian births database controls; RC: registry controls.
Includes repeated controls.