introduced on a wide basis. the fate of incoming pharmaceutical residues in the stp is unpredictable. some substances seem to be more or less completely eliminated, while others pass the different steps in the stp unaffected. there is no systematic knowledge at hand to predict how and why this happens. pharmaceutical residues that have been conjugated (bound to a bile acid) before being excreted from the patients may undergo de-conjugation in the stp, yielding higher levels of free pharmaceutical substance in the outlet from the stp than in its incoming water. some pharmaceuticals with large sales volumes have not been detected in the incoming water to the stp, indicating that complete metabolism and degradation must have occurred already in the patient or during the transport of sewage from the household to the stp. regulation united states in the united states, epa has published wastewater regulations for pharmaceutical manufacturing plants. epa has also issued air pollution regulations for manufacturing facilities. epa published regulations for hazardous waste disposal of pharmaceuticals by health care facilities in 2019. the agency also studied disposal practices for health care facilities where unused pharmaceuticals might be flushed rather than placed in solid waste, but did not develop wastewater regulations. there are no national regulations covering disposal by consumers to sewage treatment plants (i.e., disposed down the drain). to address pharmaceuticals that may be present in drinking water, in 2009 epa added three birth control substances and one antibiotic to its contaminant candidate list (ccl 3) for possible regulation under the safe drinking water act. in 2019, the united states virgin islands banned coral damaging sunscreens, in a growing trend to try to protect coral reefs. examples blister packs 80% of pills in the world are packed with blister packaging, which is the most convenient type for several reasons. blister packs have two main components, the "lid" and the "blister" (cavity). lid is mainly manufactured with aluminum (al) and paper. the cavity consists of polyvinyl chloride (pvc), polypropylene (pp), polyester (pet) or aluminum (al). if users employ proper disposal methods, all these materials can be recycled and the harmful effects to the environment can be minimized. however, a problem arises with the improper disposal either by burning or disposing as normal household waste. burning of blister packs directly causes air pollution by the combustion products of polypropylene (n), polyester (n), and polyvinyl chloride (n). the combustion reactions and products of these chemicals are mentioned below. the basic configuration of blister packaging n + 9n/2 o2 → 3n co2 +3n h2o n + 10n o2 → 10n co2 +4n h2o n + 2n o2 → n co2 + n h2o + n hcl + n co even though polypropylene and polyester is harmful to the environment, the most toxic effect is due to the combustion of polyvinyl chloride since it produces hydrochloric acid (hcl) which is an irritant in the lower and upper respiratory tract that can cause adverse effects to human beings. the disposal of blister packs as normal waste, will forbid recycling process and eventually accumulate in soil or water, which will result soil and water pollution since bio-degradation processes of compounds like pvc, pp and pet are very slow. as a result, ecologically damaging effects like disturbances of the habitats and movements can be seen. ingestion by the animals, affect the secretion of gastric enzymes and steroid hormones that can decrease the feeding stimuli and may also cause problems in reproduction. at low ph, aluminum can increase its solubility according to the following equation. as a result, the negative effects of both aquatic and terrestrial ecosystems can be generated. 2al(s)+ 6h+ → 2al3+ (aq) + 3h2 (g) by employing proper disposal methods, all manufacturing materials of blister packs like pp, pe, pvc and al can be recycled and the adverse effects to the environment can be minimized. even though, the synthesis of these polymers relatively simple, the recycling process can be very complex since the blister packs contain metals and polymers together. as the first step of recycling, separation of al and polymers using the hydrometallurgical method which uses hydrochloric acid (hcl) can be incorporated. then pvc can be recycled by using mechanical or chemical methods. the most recent trend is to use biodegradable, eco-friendly "bio plastics" which are also called as biopolymers such as derivatives of starch, cellulose, protein, chitin and xylan for pharmaceutical packaging, to reduce the hostile effects to the environment. nail polish in nail salons, employees can be exposed to dozens of chemicals found in nail polish and nail polish removers. nail polishes have many ingredients which are considered toxic, including solvents, resins, colorants and pigments, among others. in the early 2000's some of the toxic components found in nail polish (toluene, formaldehyde and dibutyl phthalate) started being replaced by other substances. one of the new components was triphenyl phosphate which is known as a endocrine-disrupting plasticizer. now many labels are available including not only 3-free but higher, for example 5-free or 12-free. there are few studies on the possible health outcomes of nail polish exposures; these include skin problems, respiratory disorders, neurologic disorders, and reproductive disorders. nail polish remover nail polish remover has the ability to enter bodies of water and soil after entering landfills or by precipitation, such as rain or snow. however, due to acetone's high volatility, most of it that enters the bodies of water and soil will evaporate again and re-enter the atmosphere. not all of the acetone molecules will evaporate again, and so, when acetone remains in the bodies of water or soil, a reaction will occur. nail polish remover evaporates easily because acetone's intermolecular forces are weak. an acetone molecule can't attract other acetone molecules easily because its hydrogens are not slightly positive. the only force that holds acetone molecules together is its permanent dipoles which are weaker than hydrogen bonds. nail polish remover contains acetone. since nail polish remover is a solvent, it will dissolve in water. when acetone dissolves in water, it hydrogen bonds with water. the more nail polish remover that enters the hydrosphere will increase the concentration of acetone and then increase the concentration of the solution created when acetone and water bonds. if enough nail polish remover is disposed, it can reach the lethal dose level for aquatic life. nail polish remover can also enter the lithosphere by landfills and by precipitation. however, it will not bind to the soil. microorganisms in the soil will decompose acetone. the consequence of microorganisms decomposing acetone is the risk it has to cause oxygen depletion in bodies of water. the more acetone readily available for microorganism decomposition leads to more microorganisms reproduced and thus oxygen depletion because more microorganisms use up the available oxygen. when nail polish remover evaporates, acetone enters the atmosphere in the gaseous phase. in the gaseous phase, acetone can undergo photolysis and breakdown into carbon monoxide, methane, and ethane. when temperatures are between 100 - 350 degrees celsius, the following mechanism occurs: (ch3)2co + hv → ch3 + ch3co ch3co → ch3+ co ch3+ (ch3)2co → ch4 + ch2coch3 2ch3 → c2h6 a second pathway that nail polish remover can enter in the atmosphere is reacting with hydroxyl radicals. when acetone reacts with hydroxyl radicals, its main product is methylglyoxal. methylglyoxal is an organic compound that is a by-product of many metabolic pathways. it is an intermediate precursor for many advanced glycation end-products, that are formed for diseases such as diabetes or neurodegenerative diseases. the following reaction occurs: (ch3)2co + ·oh → ch3c(o)oh + ·ch3 ch3c(o)oh + ·ch3→ ch3c(o)coh + 3h+ sunscreens sunscreens use a variety of chemical compounds to prevent uv radiation, like benzophenone, octocrylene, octinoxate, among others. these chemical compounds affect the life of coral reefs in different stages of their life and contributes to coral bleaching. pending questions is there a temperature at which ppcps are burned and destroyed? would they thus be eliminated when materials are made into biochar? are there artificial colorings that degrade under similar conditions to ppcps and could be used as proxies in low-tech experiments of how to eliminate ppcps? ultraviolet light is known to degrade ppcps. how long would urine need to lay in the sun in transparent bottles to destroy the ppcps before its use as fertilizer? do soil microbes develop or evolve the ability to break down ppcps over time? if a person who consumes a pharmaceutical uses a urine-diverting dry toilet, in which the urine is dispersed into fertile soil among plants, would the microbes eventually decompose this chemical entirely? after how much time? which types of pharmaceuticals would break down faster and which slower? are there types of ppcps that cannot enter into the roots of plants because their molecules are simply too large? when essential oils are extracted from plants, would ppcps pass into them, stay in the cauldron, or be destroyed by the heat?