Interest in topic:Sunlight is composed of various wavelengths of light, from ultraviolet light through infrared to visible light. Overexposure to solar radiation is recognized to have damaging and harmful effects on the human skin. Ultraviolet light is known to be the most harmful to the skin and causes sunburns, aging of the skin and skin cancer in the long run. Such light comes from the sun with radiation spectrum of 200nm -400nm. Lifestyle changes, leisure activities and holiday habits, as well as sunbathing. These trends have led to an increase in daily exposure of the skin to UV light. This leads people to use more sunscreen products to protect themselves from such UV rays.What then, is sunscreen for? The main function of sunscreen is to absorb or reflect some of the sun’s ultraviolet radiation and hence help protect us against sunburn, skin cancer and other sunlight-related health problems. Sunscreens help to filter out UV radiation using a combination of two main types of active ingredients. Commercial sunscreens often use titanium dioxide or zinc oxide particles to form a physical barrier that scatters or reflects incoming UV waves. On the other hand, natural sunscreens absorb the UV waves and release their energy as heat.Although all types of sunscreen achieve the same purpose of protecting us from UV rays, different types of sunscreens naturally are produced with differences in the properties of the sunscreen. Thus, we are interested in finding out the differences in the effectiveness of different types of sunscreen to determine which types is more beneficial and effective for the body and the reasons why. The Environmental Working Group rated 1500 sunscreen products in their 2017 annual sunscreen guide and found that about 75% of the products were either ineffective for sun protection or had chemicals that could potentially harm health and irritate the skin. The EWG also identified certain common sunscreen ingredients such as oxybenzone, homosalate and benzophenone-3 as being potentially harmful to human health. Even Vitamin A, an essential nutrient needed for our body, is harmful when exposed to UV rays. We want to find which type of sunscreen does not have, or has lesser amounts, of these ingredients. Sunscreens of different types probably have different ingredients and vitamins used in the making and refining processes. Sunscreen can vary largely in price, and we would like to find out how different sunscreens are and how much these differences affect the health in the long run to figure out which sunscreen is best for the health. As it has been found out that many fruits and vegetables have UV protection capabilities due to their antioxidant properties, we could also find out whether it is possible to make our very own sunscreens using fruits and vegetables and whether they are as effective as commercial sunscreens. Such fruits and vegetables include aloe vera, oranges, carrots. As some plants and herbs tend to be better at protecting the skin (for example, tea ameloriates adverse skin reactions from UV exposure, we can find which plants are best for the skin and health. Plants like aloe vera are found to help in the construction of new cells. Identification of issue to research:A study conducted in 2016 showed that nearly half of those surveyed looked for natural products when shopping for sunscreen. However, most consumers tend to focus only on the sunscreen’s SPF but not on the ingredients. As there are some chemicals found to be detrimental to the health in most commercial sunscreen, only looking out for the SPF value of sunscreen is not an accurate way to find which type of sunscreen is the best at protecting skin and thus an inaccurate way to choose sunscreen. With increasing consumer awareness of the risks involved with excessive sun exposure, there is a higher demand for sunscreen products to be tested and labelled. These labels could lead to a lower percentage of such health problems. When consumers are more aware and also more mindful of the health effects of using certain types of sunscreen, this could make usage of more effective sunscreens more convenient and widespread, hence reducing the number of sunlight-related diseases in the long run.Aims and Objectives:We hope that the results of our research will contribute to people’s understanding of which types of sunscreen that can be purchased in Singapore is the most beneficial for health as well as the most effectiveness, so that Singaporeans can read the labels and be more mindful of what type of sunscreen they use, instead of just buying cheaper sunscreen instead of healthier, more effective types which reflect UV radiation more effectively. If we manage to prove that some types of sunscreen are less effective and do cause health problems, this experiment may raise awareness on the importance of the ingredients used along with the SPF value of sunscreen they buy. Implications and benefits of studyThe study will imply the debunk of any urban legends about the effects of a certain types of sunscreen that is not proven correct. We and many other Singaporeans that have been choosing cheaper sunscreen to buy will be more mindful of health effects some sunscreen types will bring, and this may benefit our overall health in the long run. For those who have been aware of the differences between natural sunscreen and commercial sunscreen, we hope that this study will be able to help provide clearer and more accurate labelling of sunscreens based on the chemicals and SPF of the sunscreen to help consumers pick the best sunscreen suited to their needs.If we are able to develop a new healthy sunscreen, this would also help consumers by providing a new option of effective sunscreen for Research questions Does the percentage of vitamins and different ingredients in sunscreen affect the quality of sunscreen?What are the differences in each type of sunscreen?Do these differences affect health in positive or negative ways?Which sunscreen has the least detrimental effects and the most advantages?Research methodologyWe will research on different types of sunscreen from the same brand, keeping all variables constant except for the type of sunscreen. The effectiveness of a particular type sunscreen normally depends on its sun protection factor (the ratio of UV energy required to produce a minimal erythemal dose in protected skin to unprotected skin). One in vitro method for the calculation of a sunscreen’s SPF is to screen the absorbance of the product between 290-320 nm at every 5 nm intervals. SPF can be determined using UV spectrophotoscopy, by applying the Mansur equation shown below (Kaur and Saraf, 2010; Mishra et al.,2012):Where,CF = Correction factor (10).EE (?) = Erythmogenic effect of radiation with wave- lLength ?.Abs (?) = Spectrophotometric absorbance values atwavelength ?.The values of EE(?) x I(?) are constants, as shown in the table below: We could also try making our own natural, toxin-free, effective sunscreen from certain fruit and vegetable oils e.g. carrot seed oil, raspberry seed oil, wheat germ oil.Other natural ingredients of sunscreen include shea butter, coconut oil and green tea extract, and commercial ingredients of sunscreen include zinc oxide and titanium oxide. We will research on the effects of ingredients of each type of sunscreen, and find out whether a higher or lower percentage of each ingredient is beneficial or detrimental for the health. We can experiment on the types of sunscreen by methods like extracting a certain ingredient from the sunscreen, and finding out whether the ingredient is good for the health and more effective by researching on the effects of that ingredient and what areas of health it will affect. Chemicals in the sunscreen that could affect health include oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. We can also find out more about the refining process of each type of sunscreen and research on how much these processes affect the sunscreen and whether the effects are beneficial for the health or detrimental to the health through drawing comparisons and conclusions.Through research, we have found out that there are different types of sunscreen for different skin tones and skin types. (e.g people with acne and sensitive skin are recommended different types of sunscreen). We will research on which types of sunscreen are the best for health and the best for shielding out appropriate amounts of sunlight. Although sunscreen is for blocking out sunlight, sunlight is also important for the health as it produces large amounts of vitamin D, a vitamin which proteins in the body are unable to produce by itself. Unlike most other types of vitamins which are taken through different types of food consumed, the body is designed to take in vitamin D through exposure to sunlight. Thus, there is probably an appropriate amount of sunlight that is supposed to be taken into the body to produce vitamin D. We will find out how much sunlight is best for the skin and which type of sunscreen blocks out the right amount of sunlight.This would be an appropriate method as we can systematically list the amount of potentially damaging chemicals and other factors and compare them, hence being able to rank them according to effectiveness and healthiness. Hypothesis statementCommercial sunscreens are not as good for health as more expensive sunscreens. Some types of sunscreen are more effective than others.The difference in ingredients in sunscreens affect the vitamins in sunscreen which in turn affect the health effects of each type of sunscreen.The lesser the octocrylene, homosalate and benzophenone-3 are in sunscreen, the healthier the sunscreen is.