INDOOR RADON SURVEY IN NEPAL USING PASSIVE TECHNIQUE SOLID STATE NUCLEAR TRACK DETECTOR

Context: It has been proved from many epidemiological studies that the inhalation of the radioactive, inert gas radon (222Rn) is the main cause of lungs cancer after smoking. Objective: The survey was conducted to estimate the indoor radon concentration, the annual effective dose rate and the annual dose equivalent rate to the lung. Material and Methods: Altogether 50 dwellings were chosen randomly at 5 different districts of Nepal. The dosimetric measurements were carried out over a period of 3 months using time-integrated passive radon detectors, CR-39 based on type II Solid State Nuclear Track Detector (SSNTD) technique. The type of houses was concrete with plastered walls and mud house. Results: The minimum concentration of radon in the study areas was found to be <20Bq.m-3 and the maximum concentration was 110±20Bq.m-3. Also the corresponding values of annual effective dose and annual equivalent dose to the lung respectively varied from <0.60 to 3.30mSv.y-1 and 0.16—10-7 to 0.88×10-7 Sv.y-1. The uncertainty was measured at 95% confidence level. Conclusion: The indoor radon concentration varies considerably with the ventilation condition, lifestyle of the people, construction of the dwellings and climate of the areas. The measurements show that the radon concentrations were found to be well below the reference levels of ICRP. KEYWORDS: Indoor Radon; Annual Effective Dose; CR-39; Ventilation Condition; Dwelling

INDOOR RADON SURVEY IN NEPAL USING PASSIVE TECHNIQUE SOLID STATE NUCLEAR TRACK DETECTOR

Context: It has been proved from many epidemiological studies that the inhalation of the radioactive, inert gas radon (222Rn) is the main cause of lungs cancer after smoking. Objective: The survey was conducted to estimate the indoor radon concentration, the annual effective dose rate and the annual dose equivalent rate to the lung. Material and Methods: Altogether 50 dwellings were chosen randomly at 5 different districts of Nepal. The dosimetric measurements were carried out over a period of 3 months using time-integrated passive radon detectors, CR-39 based on type II Solid State Nuclear Track Detector (SSNTD) technique. The type of houses was concrete with plastered walls and mud house. Results: The minimum concentration of radon in the study areas was found to be <20Bq.m-3 and the maximum concentration was 110±20Bq.m-3. Also the corresponding values of annual effective dose and annual equivalent dose to the lung respectively varied from <0.60 to 3.30mSv.y-1 and 0.16—10-7 to 0.88×10-7 Sv.y-1. The uncertainty was measured at 95% confidence level. Conclusion: The indoor radon concentration varies considerably with the ventilation condition, lifestyle of the people, construction of the dwellings and climate of the areas. The measurements show that the radon concentrations were found to be well below the reference levels of ICRP. KEYWORDS: Indoor Radon; Annual Effective Dose; CR-39; Ventilation Condition; Dwelling

Household food production is positively associated with dietary diversity and intake of nutrient-dense foods for older preschool children in poorer families: Results from a nationally-representative survey in Nepal.

Nutrition-sensitive interventions supporting enhanced household food production have potential to improve child dietary quality. However, heterogeneity in market access may cause systematic differences in program effectiveness depending on household wealth and child age. Identifying these effect modifiers can help development agencies specify and target their interventions.This study investigates mediating effects of household wealth and child age on links between farm production and child diets, as measured by production and intake of nutrient-dense food groups.Two rounds (2013 and 2014) of nationally representative survey data (n = 5,978 observations) were used to measure production and children's dietary intake, as well as a household wealth index and control variables, including breastfeeding. Novel steps used include measuring production diversity in terms of both species grown and food groups grown, as well as testing for mediating effects of family wealth and age of child.We find significant associations between child dietary diversity and agricultural diversity in terms of diversity of food groups and of species grown, especially for older children in poorer households, and particularly for fruits and vegetables, dairy and eggs. With each additional food group produced, log-odds of meeting minimum dietary diversity score (≥4) increase by 0.25 (p = 0.01) for children aged 24-59 months. For younger children aged 18-23 months there is a similar effect size but only in the poorest two quintiles of household wealth, and for infants 6-18 months we find no correlation between production and intake in most models.Child dietary intake is associated with the composition of farm production, most evident among older preschool children and in poorer households. To improve the nutrition of infants, other interventions are needed; and for relatively wealthier households, own farm production may displace market purchases, which could attenuate the impact of household production on child diets

Diet diversity and agricultural diversity quintile produced by child's age (unbalanced panel).

<p>Diet diversity and agricultural diversity quintile produced by child's age (unbalanced panel).</p

Household dairy production and consumption.

<p>Household dairy production and consumption.</p

Diet diversity and number of food groups produced by child's age.

<p>Diet diversity and number of food groups produced by child's age.</p

Household egg production and consumption.

<p>Household egg production and consumption.</p

Household legumes production and consumption.

<p>Household legumes production and consumption.</p

Household fruit and vegetable production and consumption.

<p>Household fruit and vegetable production and consumption.</p

Child dietary diversity by child age (in month).

<p>Box plots show median, 25^th and 75^th percentile of distributions, and diamonds represent mean for each age range.</p