La roca magica: uses of natural zeolites in agriculture and industry.
(1/16)
For nearly 200 years since their discovery in 1756, geologists considered the zeolite minerals to occur as fairly large crystals in the vugs and cavities of basalts and other traprock formations. Here, they were prized by mineral collectors, but their small abundance and polymineralic nature defied commercial exploitation. As the synthetic zeolite (molecular sieve) business began to take hold in the late 1950s, huge beds of zeolite-rich sediments, formed by the alteration of volcanic ash (glass) in lake and marine waters, were discovered in the western United States and elsewhere in the world. These beds were found to contain as much as 95% of a single zeolite; they were generally flat-lying and easily mined by surface methods. The properties of these low-cost natural materials mimicked those of many of their synthetic counterparts, and considerable effort has made since that time to develop applications for them based on their unique adsorption, cation-exchange, dehydration-rehydration, and catalytic properties. Natural zeolites (i.e., those found in volcanogenic sedimentary rocks) have been and are being used as building stone, as lightweight aggregate and pozzolans in cements and concretes, as filler in paper, in the take-up of Cs and Sr from nuclear waste and fallout, as soil amendments in agronomy and horticulture, in the removal of ammonia from municipal, industrial, and agricultural waste and drinking waters, as energy exchangers in solar refrigerators, as dietary supplements in animal diets, as consumer deodorizers, in pet litters, in taking up ammonia from animal manures, and as ammonia filters in kidney-dialysis units. From their use in construction during Roman times, to their role as hydroponic (zeoponic) substrate for growing plants on space missions, to their recent success in the healing of cuts and wounds, natural zeolites are now considered to be full-fledged mineral commodities, the use of which promise to expand even more in the future. (+info)
Antiperspirant use and the risk of breast cancer.
(2/16)
The rumor that antiperspirant use causes breast cancer continues to circulate the Internet. Although unfounded, there have been no published epidemiologic studies to support or refute this claim. This population-based case- control study investigated a possible relationship between use of products applied for underarm perspiration and the risk for breast cancer in women aged 20-74 years. Case patients (n = 813) were diagnosed between November 1992 and March 1995; control subjects (n = 793) were identified by random digit dialing and were frequency-matched by 5-year age groups. Product use information was obtained during an in-person interview. Odds ratios (ORs) and 95% confidence intervals were estimated by the use of conditional logistic regression. P values were determined with the Wald chi(2) test. All statistical tests were two-sided. The risk for breast cancer did not increase with any of the following activities: 1) antiperspirant (OR = 0.9; P =.23) or deodorant (OR = 1.2; P =.19) use; 2) product use among subjects who shaved with a blade razor; or 3) application of products within 1 hour of shaving (for antiperspirant, OR = 0.9 and P =.40; for deodorant, OR = 1.2 and P =.16). These findings do not support the hypothesis that antiperspirant use increases the risk for breast cancer. (+info)
Antiperspirant drug products for over-the-counter human use; final monograph. Final rule.
(3/16)
The Food and Drug Administration (FDA) is issuing a final rule in the form of a final monograph establishing conditions under which over-the-counter (OTC) antiperspirant drug products are generally recognized as safe and effective and not misbranded as part of FDA's ongoing review of OTC drug products. FDA is issuing this final rule after considering public comments on its proposed regulation, issued as a tentative final monograph (TFM), and all new data and information on antiperspirant drug products that have come to the agency's attention. (+info)
Current therapeutic options for treating primary hyperhidrosis.
(4/16)
Severe hyperhidrosis can cause extreme embarrassment that may lead to social and professional isolation. Therapeutic strategies to hyperhidrosis should employ the least invasive treatment that provides effective symptom control. The treatment options available for control of hyperhidrosis, non-surgical or surgical, differ in their invasiveness and efficacy. Mechanisms of action of antiperspirants, iontophoresis, cholinergic inhibitor drugs, botulinum toxin, and surgical sympathectomy are reviewed. There is little published evidence in the form of comparative randomised trials to support the use of one treatment over another. However, authors have tended to recommend those therapies that are available to their speciality. Specific therapies should be tailored to the patient's symptoms to gain maximum symptomatic improvement with minimum invasiveness and side-effects. To achieve this, the full range of treatment options should be available to, or accessible by the consulting doctor in order for the patient to have a meaningful choice. (+info)
Butane encephalopathy.
(5/16)
Volatile solvent abuse (VSA) is defined at the "intentional inhalation of a volatile substance for the purpose of achieving a euphoric state". The lifetime prevalence of VSA in the UK remains steady at around 15%, the fourth highest rate in Europe, and VSA is the most common form of drug abuse in the 11-15 year age group in England and Wales. A 13 year old girl presented to the accident and emergency unit following inhalation of butane based deodorant, which resulted in a prolonged semiconscious state with encephalopathic symptoms. (+info)
Health effects of indoor odorants.
(6/16)
People assess the quality of the air indoors primarily on the basis of its odors and on their perception of associated health risk. The major current contributors to indoor odorants are human occupant odors (body odor), environmental tobacco smoke, volatile building materials, bio-odorants (particularly mold and animal-derived materials), air fresheners, deodorants, and perfumes. These are most often present as complex mixtures, making measurement of the total odorant problem difficult. There is no current method of measuring human body odor, other than by human panel studies of expert judges of air quality. Human body odors have been quantitated in terms of the "olf" which is the amount of air pollution produced by the average person. Another quantitative unit of odorants is the "decipol," which is the perceived level of pollution produced by the average human ventilated by 10 L/sec of unpolluted air or its equivalent level of dissatisfaction from nonhuman air pollutants. The standard regulatory approach, focusing on individual constituents or chemicals, is not likely to be successful in adequately controlling odorants in indoor air. Besides the current approach of setting minimum ventilation standards to prevent health effects due to indoor air pollution, a standard based on the olf or decipol unit might be more efficacious as well as simpler to measure. (+info)
Urinary and air phthalate concentrations and self-reported use of personal care products among minority pregnant women in New York city.
(7/16)