Multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerances (IEI), is an unrecognized and controversial diagnosis characterized by chronic symptoms attributed to exposure to low levels of commonly used chemicals. Symptoms are typically vague and non-specific. They may include fatigue, headaches, nausea, and dizziness. Although these symptoms can be debilitating, MCS is not recognized as an organic, chemical-caused illness by the World Health Organization, American Medical Association, nor any of several other professional medical organizations. Blinded clinical trials show that people with MCS react as often and as strongly to placebos as they do to chemical stimuli; the existence and severity of symptoms is seemingly related to the perception that a chemical stimulus is present.Commonly attributed substances include scented products (e.g. perfumes), pesticides, plastics, synthetic fabrics, smoke, petroleum products, and paint fumes. Symptoms
Symptoms are typically vague and non-specific, such as fatigue or headaches. These symptoms, although they can be disabling, are called non-specific because they are not associated with any single specific medical condition. A 2010 review of MCS literature said that the following symptoms, in this order, were the most reported in the condition: headache, fatigue, confusion, depression, shortness of breath, arthralgia, myalgia, nausea, dizziness, memory problems, gastrointestinal symptoms, respiratory symptoms.Symptoms mainly arise from the autonomic nervous system (such as nausea or dizziness) or have psychiatric or psychological aspects (such as difficulty concentrating).
Society and culture

The curvature of the female back is a frequent theme in paintings, because the sensibilities of many cultures permit the back to be shown nude - implying full nudity without actually displaying it. Indeed, the practice of showing explicitness on the lower back has been performed for centuries. Certain articles of clothing, such as the haltertop and the backless dress, are designed to expose the back in this manner. The lower back is typically exposed frequently by many types of shirts in womans fashion, and even the more conservative shirts and blouses will reveal the lower back. This happens for a variety of reasons- the lower waist area is a pivot point for the body and lengthens and arches as a person sits or bends. Secondly, womans fashion typically favors tops that are waist length, allowing the back to be left bare during slight movement, bending or sitting. The back also serves as the largest canvas for body art on the human body. Because of its size and the relative lack of hair, the back presents an ideal canvas on the human body for lower back tattoos, mostly among young women. Indeed, some individuals have tattoos that cover the entirety of the back. Others have smaller tattoos at significant locations, such as the shoulder blade or the bottom of the back.