Artificial night light and thyroid cancer

Figure 1 Plots of adjusted standardized rate for thyroid cancer, taking into account quality of cancer registries level. A: By gross domestic product per person quartile; B: By health expenditure per person quartile; horizontal lines indicate the 25^thand 75^th percentiles, respectively, with the median in between. GDP: Gross domestic product; HEP: Health expenditure per person.

Figure 2 Plots of artificial light at night exposure percentages (vertical scale), by area or population. A: By gross domestic product per person quartile; B: By health expenditure per person quartile; boxplots are framed by the 25^thand 75^th percentile. GDP: Gross domestic product; HEP: Health expenditure per person.

Figure 3 Scatterplots of thyroid cancer incidence by level of exposure to artificial light at night, with locally weighted scatterplot smoothing curves. A: Thyroid cancer (TC) incidence versus percentage of country population exposed to artificial light at night > 87 μcd/m²; B: TC incidence versus percentage of country population exposed to artificial light at night > 688 μcd/m²; C: TC incidence versus percentage of country area exposed to artificial light at night > 87 μcd/m²; D: TC incidence versus percentage of country area exposed to artificial light at night > 688 μcd/m²; ASR Thyr Ca: Adjusted standardized rate of TC incidence per 100000 population.