EFFECT OF UV-B RADIATION ON CILIATED PROTOZOA - Environmental UV Radiation: Impact on Ecosystems and Human Health and Predictive Models - page 233

2,0

1,8

1,6

1,4

1,2

1,0

0,8

0,6

0,4

0,2

0,0

0 15 30 45 60 75 90 105 120 135 150

Time [min]

Fig. 9. Dose-effect curves of Fabrea salina phototaxis. Circles: samples irradiated with UV-B, UV-A
and visible light; squares: control 1 samples, irradiated with UV-A and visible light; triangles: control
2 samples, irradiated with visible light only (redrawn from ref. 19).

1,20

1,00

0,80

Phototaxis
(relative units)

0,60

0,40

0,20

0,00

3'45"

7'30"

15'

B

0

30'

1

2 60'

3

Recovery
time [h]

120'

4

Exposure time [min]

Fig. 10. 3D histogram of the phototaxis of UV-irradiated samples of F. salina cells, as a function of
both irradiation time and time elapsed after irradiation. Data are reported as described in Fig. 5.
(Redrawn from ref. 19).

Figure 11 shows the dose-effect curves of phototactic sensitivity (that is the
phototactic response of a sample as a function of increasing phototaxis-stimulating light
intensity) for samples irradiated with UV-B, UV-A and visible light for 30 min and for
control samples. From these curves, it is clear that the phototactic response of irradiated