We know that increased exposure to UV-B radiation has specific effects on human health, crops, terrestrial ecosystems, aquatic ecosystems, and biogeochemical cycles
The effects of UV-B radiation on human skin are varied and widespread. UV-B induces skin cancer by causing mutation in DNA and suppressing certain activities of the immune system. The United Nations Environment Program estimates that a sustained 1 percent depletion of ozone will ultimately lead to a 2-3 percent increase in the incidence of non-melanoma skin cancer. UV-B may also suppress the body’s immune response to Herpes simplex virus and to skin lesion development, and may similarly harm the spleen.
Our hair and clothing protect us from UV-B, but our eyes are vulnerable. Common eye problems resulting from over-exposure to UV-B include cataracts, snow blindness, and other ailments, both in humans and animals. While many modern sunglasses offer some UV protection, a significant amount of UV can still reach our eyes in a high exposure situation.
With regard to plants, UV-B impairs photosynthesis in many species. Overexposure to UV-B reduces size, productivity, and quality in many of the crop plant species that have been studied (among them, many varieties of rice, soybeans, winter wheat, cotton, and corn). Similarly, overexposure to UV-B impairs the productivity of phytoplankton in aquatic ecosystems. UV-B increases plants’ susceptibility to disease. Scientists have found it affects enzyme reactions that conduct fundamental biological functions, it impairs cellular division in developing sea urchin eggs, and it changes the movements and orientation of tiny organisms as they move through ocean waters. Since some species are more vulnerable to UV-B than others, an increase in UV-B exposure has the potential to cause a shift in species composition and diversity in various ecosystems. Because UV-B affects organisms that move nutrients and energy through the biosphere, we can expect changes in their activities to alter biogeochemical cycles. For example, reducing populations of phytoplankton would significantly impact the world’s carbon cycle, because phytoplankton store huge amounts of carbon in the ocean.
The variability of the sun's ultraviolet radiation
The intensity of continua and emission lines which form the solar UV spectrum below 2100 Å is variable. Continua and emission lines originating from different layers in the solar atmosphere show a different degree of variability. Coronal emission lines at short wavelengths are much more variable than continua at longer wavelengths which originate in lower layers of the solar atmosphere. Typical time-scales of solar UV variability are minutes (flare induced), days (birth of active regions), 27 days (solar rotation), 11 years (solar cycle) and perhaps centuries, caused by long-term changes of the solar activity. UV intensity variations have been determined by either absolute irradiance measurements or by contrast measurements of plages vs. the quiet sun. Plages are the main contributor to the solar UV variability. Typical values for the solar UV variability over a solar cycle are: <1% at wavelengths longer than 2100 Å, 8% at 2080 Å (continuum), 20% at 1900 Å (continuum), 70% at H Lyα, 200% in certain emission lines 1200 < λ < 1800 Å and more than a factor of 4 in coronal lines λ < 1000 Å. Plage models predict the variable component of the solar UV radiation within ±50%. Absolute fluxes are known within ±30%. Several efforts are underway to monitor the solar UV irradiance with a precision better than a few percent over a solar activity cycle.
It is the average lifespan under typical thermal conditions in the Central Mediterranean climate. INSON SHADE’S fabric have UV stability of 500 kLy (kilo – Langley).
The intensity of UV radiation is measured in kLy (kilo – Langley), a unit that represents the amount of UV radiation that falls on a cm2 per year.
The intensity of UV radiation is variable and, as you can see from the map, depends largely on geographical location.
So,INSON SHADE’s add ANTIOXIDANT when making the shade fabric.
Their purpose is to protect polymers from thermo-oxidative degradation both during the manufacturing process (short stabilization) and during the subsequent transformation phases.
Antioxidant additives act also long-term, preserving the characteristics of the finished product.
During the production process, heating polymers creates free radicals that modify the chemical structure of the resins by generating gels and changing the length of polymer chains, resulting in loss and/or deterioration of their mechanical characteristics (change of MFI, worsening of gloss) and of their aesthetic properties, including discoloration.