Looks like Seasonal Affective Disorder has a whole new meaning

         Seasonal Affective Disorder is characterized as short term depression during the months of winter where the nights are long and days are short. Circadian Rhythms are the body's inner biological clock that helps indicate when to sleep, eat, and wake, essentially helping us keep track of time. With certain environmental cues, our bodies work accordingly. For instance, melatonin, a sleep inducing hormone in our body, is released when the our retina receives feedback that it is nighttime. During the long-enduring months of winter, many people fall ill of depression since the body undergoes a state of hibernation and chronic fatigue. Typically one cure for S.A.D. requires light therapy which entails the victim to expose oneself to safe measure of UV rays with artificial lighting. 

There are a myriad of other ways that can affect our circadian rhythm's sleep cycle such as eating too late in the night (and other irregular feeding behaviors), sleeping under too cold or too hot conditions, as well as being genetically predispositioned to an irregular biological clock that fails to code for downstream regulations. Irregular circadian rhythms have a high correlation with many human diseases such as heart disease, diabetes, and cancer.  

However, recent news, has added another factor into our list: road salt. High salinity is affecting microorganisms called Daphnia which are important for algae consumption and are also a huge source of nutrition for fish. Such as how light intensity drives our clock, the mechanics of "dial vertigo migration" works the same for this species and is disrupted by road salt pollution. This term refers to the daily biomass movement in lakes (e.g. tides). By polluting this habit, the ecosystem leading up to our feeding grounds are disrupted as well. Future studies are now looking at other environmental pollutants that may be endangering species such as our own. A midst all this calamity, one can truly imagine how fragile life's balance can be and above all, the importance of diet and sleep.

References:

Hurley, J. M. (2018, January 04). Can Road Salt and Other Pollutants Disrupt Our Circadian 

        Rhythms? Retrieved from https://www.scientificamerican.com/article/can-road-salt-and-other-   

       pollutants-disrupt-our-circadian-rhythms/

King, A. N., Barber, A. F., Smith, A. E., Dreyer, A. P., Sitaraman, D., Nitabach, M. N., . . . Sehgal, A. 

        (2017). A Peptidergic Circuit Links the Circadian Clock to Locomotor Activity. Current     

        Biology,27(13). doi:10.1016/j.cub.2017.05.089