Characteristics of indoor/outdoor particulate pollution in urban and rural residential environment of Pakistan

Particulate pollution has emerged as a serious environmental health concern in Pakistan. The use of biomass fuels in traditional stoves produces high levels of indoor air pollutants. In Pakistan, 94% of rural and 58% of urban households depend on biomass fuel. This study investigates variations in indoor/outdoor concentrations of particulate matter during various activities for three different micro-environments in Pakistan. At a rural site, the average indoor/outdoor ratios for PM10, PM2.5, and PM 1, in kitchens using biomass fuels were 3.80, 4.36, and 4.11, respectively. A large variation was recorded in the mass concentration of particulate matter during cooking with concentrations in the range 4000-8555 μg/m3. In a living room at a rural site, the average indoor/outdoor ratios for PM10, PM2.5, and PM1 were 1.74, 2.49, and 3.01, respectively. At the urban site, the average indoor/outdoor ratios for the same size fractions were 1.71, 2.88, and 3.47, respectively. Cooking, cleaning and smoking were identified as principal contributors to the high indoor levels of particulate matter. This study showed considerably high concentrations of particulate matter, particularly in kitchens using biomass fuels, as compared to living areas. Thus women and children face the greatest exposure due to the amount of time they spend in the kitchen. Practical Implications In the developing world, particulate air pollution, both indoor and outdoor, is a substantial health hazard to the public. The very high concentrations of particulate matter in both rural and urban sites, particularly in kitchens using biomass fuels emphasize the severity of this issue in Pakistan. Women and children are extensively at risk due to amount of time spent in kitchens. This state of affairs calls for a large-scale intervention to reduce the exposure to indoor air pollution. © 2009 John Wiley & Sons A/S

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013 . Scientific opinion on Dietary Reference Values for fluoride

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for fluoride, which are provided as Adequate Intake (AI) from all sources, including non-dietary sources. Fluoride is not an essential nutrient. Therefore, no Average Requirement for the performance of essential physiological functions can be defined. Nevertheless, the Panel considered that the setting of an AI is appropriate because of the beneficial effects of dietary fluoride on prevention of dental caries. The AI is based on epidemiological studies (performed before the 1970s) showing an inverse relationship between the fluoride concentration of water and caries prevalence. As the basis for defining the AI, estimates of mean fluoride intakes of children via diet and drinking water with fluoride concentrations at which the caries preventive effect approached its maximum whilst the risk of dental fluorosis approached its minimum were chosen. Except for one confirmatory longitudinal study in US children, more recent studies were not taken into account as they did not provide information on total dietary fluoride intake, were potentially confounded by the use of fluoride-containing dental hygiene products, and did not permit a conclusion to be drawn on a dose-response relationship between fluoride intake and caries risk. The AI of fluoride from all sources (including non-dietary sources) is 0.05 mg/kg body weight per day for both children and adults, including pregnant and lactating women. For pregnant and lactating women, the AI is based on the body weight before pregnancy and lactation. Reliable and representative data on the total fluoride intake of the European population are not available