Chromosome instability in lymphocytes of Friesian cows naturally exposed to dioxins being raised close to a metallurgic factory area in southern Italy

Figures & data

Figure 1. Farm raising Friesian cattle very close to the metallurgic industrial area of Taranto city.

Table 1. Levels of PCDD + PCDFs, DL-PCBs and sum of PCDD + PCDF + DL-PCBs in the milk mass of the farm under legal sequestration, as well as in the grass and soil of the same farm. Permitted values of dioxins are reported between parentheses.

Source	PCDD + PCDF WHO-TEQ (pg g^−1)	DL-PCBs WHO-TEQ (pg g^−1)	PCDD + PCDF+ DL-PCBs WHO-TEQ(pg g^−1)
Milk mass	4.22 ± 0.58 (2.5)	20.56 ± 2.53	24.78 ± 3.19 (5.5)
Grass	0.83 (0.75)	1.54	2.37 (1.5)
Soil	2.49 ± 0.53 (10)	0.23 ± 0.04

Figure 2. Female cattle metaphase plate showing a chromatid break (arrow). Slides were stained with acridine orange and later observed under a fluorescence microscope connected with a digital camera.

Table 2. Number of animals studies, examined cells, abnormal cells (AC), chromatid breaks (CT), chromosome breaks (CS), and total CT + CS in cattle reared in dioxin-contaminated and control areas of Apulian region (southern Italy).

Animals (n)	Examined cells(n)	Abnormal cells (AC)		Chromatid breaks (CT)		Chromosome breaks (CS)		CT + CS
		n	mean ± SD	n	mean ± SD	n	mean ± SD	n	mean ± SD
Exposed – total (28)	980	508	0.52 ± 0.49^a	704	0.72 ± 0.86^a	69	0.07 ± 0.28^a	773	0.79 ± 0.92^a
Control – total (20)	700	112	0.16 ± 0.37	105	0.15 ± 0.39	17	0.02 ± 0.15	122	0.17 ± 0.42

^a Significantly higher versus controls (p < 0.01)

Figure 3. Female cattle metaphase plate showing several SCEs (arrows). Slides were stained with acridine orange and later observed under a fluorescence microscope connected with a digital camera.

Table 3. Number of examined cells and SCE mean values in Friesian dairy cows reared in dioxin-contaminated and control areas of Apulian region (southern Italy).

Animals (n)	Examined cells (n)	SCE/cell
		n	Mean ± SD
Exposed (29)	870	6450	7.41 ± 3.02^a
Control (23)	690	3660	5.30 ± 2.61

^a Significantly higher versus control (p < 0.01)

Table 4. Descriptive statistics.

	Control				Exposed
Variables	CS	CT	CT+CS	SCE	CS	CT	CT+CS	SCE
Mean	0.0243	0.1500	0.1743	5.0343	0.0704	0.7183	0.7888	7.4138
Var	0.0237	0.1563	0.1756	6.8158	0.0798	0.7398	0.8532	9.1266
Median	0	0	0	5	0	0	1	7
Range	0–1	0–3	0–3	0–24	0–2	0–4	0–5	0–32
n	700	700	700	690	980	980	980	870

Figure 4. The histograms of variables showing a no normal distribution.

Table 5. Shapiro Wilk test for normality.

	Control				Exposed
Variables	CS	CT	CT+CS	SCE	CS	CT	CT+CS	SCE
Score	0.1373	0.4140	0.4511	0.9455	0.2601	0.7735	0.7865	0.9531
P-value	2.2e-16	2.2e-16	2.2e-16	3.084e-15	2.2e-16	2.2e-16	2.2e-16	5.055e-16

H₀: The variable is distributed as a normal.

Table 6. Mann–Whitney non-parametric test for equality of means.

	Control versus exposed
Variables	CS	CT	CT+CS	SCE
SCORE	356429.5	472458.5	475338.5	427537.5
P-value	9.35e-05	2.2e-16	2.2e-16	2.2e-16

H₀: Control and exposed groups are from the same population and have the same mean.

Table 7. Permutation test for equality of deviance.

	Control versus exposed
Variables	CS	CT	CT+CS	SCE
SCORE	2.9	4.8	4.3	1.2
P-value	1e-04	1e-04	1e-04	3e-04

H₀: Control and exposed groups are from the same population and have the same deviance.

Figure 5. Deviance of exposed CT+CS and CT from the control sample distributions.