Pyrethroids are a class of widely used insecticides. Female animal studies suggested that pyrethroid exposure impaired ovarian function, which resulted in similar symptoms of primary ovarian insufficiency (POI). However, it is still unknown whether this association applies to women. In this case-control study, a total of 172 POI patients and 247 control women were recruited in Zhejiang, China. The urinary concentrations of metabolites of pyrethroids, 3-phenoxybenzoic acid (3-PBA) and 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA), as well as the serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and anti-Mullerian hormone (AMH) were determined. The associations of pyrethroid metabolites with POI and POI-related hormones were accessed using unconditional logistic regression. Higher urinary levels of 3-PBA were significantly associated with increased risk of POI [adjusted odds ratio (OR) = 2.344, 95% CI: 1.193-4.607 for the highest vs lowest quartile of 3-PBA, p = 0.013]. Stratified analyses showed that each log increase in urinary 3-PBA concentration was significantly associated with an induction in odds of 51.0% being in the highest quartile of FSH and 28.6% being in the highest quartile of LH levels, whereas a 25.9% reduction in odds of being in the highest quartile of AMH levels (All p for trend <0.05). To our knowledge, this is the first case-control study to report an association of pyrethroid exposure with increased risk of POI in women.

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The purpose of this study was to investigate the perception of neutral white and chromatic adaptation on a display under ambient lighting conditions with different chromaticities and illuminance levels. The desktop display was arranged to simulate a mobile phone. The neutral white was the whitest point that excluded chromatic color. Only one original image was used and it comprised black text against a white background under CIE illuminant D65 and the CIE 1964 standard colorimetric observer. Forty-two rendered images were made to cover a representative area of chromaticity space that might be considered white. Eleven ambient lighting conditions were applied with five values of correlated color temperature (3000, 4000, 5000, 6000, and 8000 K) each at two illuminance levels (500 and 1000 lx) plus a dark condition. A psychophysical experiment was conducted where observers were asked to judge each image in terms of "neutrality" under each ambient lighting condition. The results showed that there were significant differences between different ambient lighting conditions. All the available data including the present were used to develop an incomplete chromatic adaptation function with different scaling factors for the incomplete adaptation factor (D) in CAT02. The function suggests that the illuminance and chromaticity of the illuminant had a clear trend on chromatic adaptation. However, the degree of adaptation is affected by the viewing conditions in each experiment.

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