 In addition to meat, exposure to common household chemicals may exacerbate or induce allergies, asthma, and eczema. Researchers at Harvard and all around the world collected air samples from where children slept, and demonstrated for the first time that the bedroom concentration of propylene glycol and glycol ethers was significantly associated with an elevated risk of multiple allergic symptoms, polynose, and eczema. This class of chemical compounds is found in cleaning fluids, pain, pesticides, PVC pipes, varnishes, and may be one of the reasons we've seen an increase in these kinds of diseases around the world over the last few decades. Recently, researchers put a few consumer products to the test. Air professionals, a laundry detergent, fabric softener, and dryer sheets each with annual sales over $100 million. Six products, nearly 100 volatile chemicals, identified, though none were listed on the labels, usually just says something like fragrance. And 10 of the chemicals they found are regulated as toxic or hazardous, with three officially classified as hazardous air pollutants. For example, the fabric softener they tested. On the label it just says biodegradable fabric softening agents. And it even smells like mom when she leans in for a good night kiss. But this is what they really found, including the carcinogenic hazardous air pollutant, acetaldehyde. What about if you just stick to the naturally scented products? Human products advertised as green, natural, organic, emitted as many hazardous chemicals as standard ones. For example, soap boasting, pure essential oils, and organic tea infusions also contained all of these. Yeah, but what if you somehow know for certain it's all just natural, like the limonene, right? That's a real phytochemical found in real citrus. Until it photooxidized with ozone and ambient air to form dangerous secondary pollutants, including formaldehyde. When it comes to consumer products, the best smell is no smell.