High Radon Areas and lung cancer prevalence: Evidence from Ireland

Behaviourally-informed household communications increase uptake of radon tests in a randomised controlled trial

Exposure to radon gas is a leading cause of lung cancer. Testing homes for the gas is straightforward, yet most people do not undertake tests even when offered freely. We report a pre-registered randomised controlled trial of communications to encourage test uptake. Households (N = 3500) in areas at high risk of radon exposure were randomly assigned to receive (i) a the control letter from the national Environmental Protection Agency; (ii) a behaviourally-informed version of the control letter that incorporated multiple nudges, including reciprocity messages and numeric frequencies of risk; (iii) this same behaviourally-informed letter in a re-designed envelope; (iv) the behaviourally-informed letter in the re-designed enveloped with a radon risk map of the household's county. The behaviourally-informed letter led to a large increase in test uptake, from 22% in the control condition to 33% (a 50% increase). There was no additional benefit of the re-designed envelope, which generated uptake of 30%. Including the map led some households to respond faster, but the overall uptake (26%) was weaker. The results have implications for public health communications with households and show the potential for techniques from behavioural science to help mitigate environmental risks.

Radiation Protection of Polydatin Against Radon Exposure Injury of Epithelial Cells and Mice

Radon exposure is significantly associated with lung cancer. Radon concentration is currently reduced mainly by physical methods, but there is a lack of protective drugs or biochemical reagents for radon damage. This study aimed to explore the protective effect of polydatin (PD) on the radon-exposed injury. The results showed that PD can significantly reduce ROS level, raise SOD activity, weaken the migration ability, increase E-cad, and decrease mesenchymal cell surface markers (FN1, Vimentin, N-cad, α-SMA, and Snail) in radon-exposed epithelial cells. In vivo, PD increased the mice weight, promoted SOD activity, and decreased MDA content, the number of bullae, pulmonary septum thickness, lung collagenous fibers, and mesenchymal cell surface markers. Furthermore, PD inhibited p-PI3K, p-AKT, and p-mTOR expression. Compared with directly adding PD on radon-exposed cells, adding PD before and after radon exposure could more obviously improve the adhesion of radon-exposed cells, significantly alleviate the migration ability, and more significantly reduce mesenchyme markers and p-AKT and p-mTOR. These results indicate that PD can reduce oxidative stress, weaken epithelial-mesenchymal transition (EMT) and lung fibrosis in radon-exposed cells/mice, and have good radiation protection against radon injury. The mechanism is related to the inhibition of the PI3K/AKT/mTOR pathway.

Analysis of Indoor Radon Data Using Bayesian, Random Binning, and Maximum Entropy Methods

Three statistical methods: Bayesian, randomized data binning and Maximum Entropy Method (MEM) are described and applied in the analysis of US radon data taken from the US registry. Two confounding factors-elevation of inhabited dwellings, and UVB (ultra-violet B) radiation exposure-were considered to be most correlated with the frequency of lung cancer occurrence. MEM was found to be particularly useful in extracting meaningful results from epidemiology data containing such confounding factors. In model testing, MEM proved to be more effective than the least-squares method (even via Bayesian analysis) or multi-parameter analysis, routinely applied in epidemiology. Our analysis of the available residential radon epidemiology data consistently demonstrates that the relative number of lung cancers decreases with increasing radon concentrations up to about 200 Bq/m³, also decreasing with increasing altitude at which inhabitants live. Correlation between UVB intensity and lung cancer has also been demonstrated.

Housing Risk Factors Associated with Respiratory Disease: A Systematic Review

Cold, damp and mouldy housing arises from the degradation of the housing stock over time due to weathering and a lack of maintenance. Living in such houses is associated with many adverse impacts on human health, especially for those with existing health issues. This paper presents a systematic review, using the PRISMA protocol, consisting of an exploratory analysis of housing-related risk factors associated with respiratory disease. The review consisted of 360 studies investigating 19 risk factors associated with respiratory conditions. Each fall into one of four categories, namely, (1) outdoor environment-related factors; (2) indoor air pollution-related factors; (3) housing non-structure-related factors; or (4) housing structure-related factors. The results show that effects of poor housing conditions on occupants’ respiratory health is a growing research field, where poor indoor air quality, mainly due to a lack of adequate ventilation, was found to be the most influential risk factor. Usage of solid fuel and living in an urban area without a pollutant-free air filtration system are the main risk factors related to inadequate ventilation. Therefore, an adequate and reliable ventilation system with air-infiltration was considered to be the main mitigation solution to improve indoor air quality. It is suggested that government organisations and health practitioners could use the identified risk factors to measure the healthiness of existing dwellings and take measures to improve existing conditions and develop regulations for new housing construction to promote the healthy home concept. Further research is needed for risk mitigation strategies to reduce the respiratory health burden attributed to housing.

Identifying indoor radon sources in Pa Miang, Chiang Mai, Thailand

Radon is the leading source of lung cancer mortality after smoking in Chiang Mai, Thailand. Finding a source of carcinogens is one of the important measures for preventing the cancer risk for this region. Specific sites at Pa Miang, Doi Saket have the highest incidences of lung cancer and have a combination of factors that influence indoor radon concentration. Our study identified the sources of indoor radon within several houses. The results indicate that geological and topographic characteristics, including active faults and mountain terraces, are the main sources of indoor radon, especially for wooden houses. Besides building materials, the design of the houses, ventilation conditions, and lifestyle choices are all factors influencing indoor radon concentrations and its associated risk. Although radon levels (29–101 Bq m⁻³) and total indoor annual effective doses (0.9–3.8 mSv year⁻¹) received from all sources at these sites have shown no significant health risk due to radon exposure , this investigation will be useful as a starting point to guide strategies to respond and prevent the risk of lung cancer, especially in Chiang Mai.

A case study on the correlation between radon and multiple geophysicochemical properties of soils in G island, Korea, and effects on the bacterial metabolic behaviors

This study was conducted to assess the natural radiation intensity of radon observed from 'G' islands and its effects against Bacillus pumilus, predominantly found throughout the field survey. The physicochemical properties and microbial characteristics were simultaneously investigated and compared. From these studies, it was confirmed that the areal distribution of radon concentration varied from 920 Bq/m³ to 3367 Bq/m³ depending on the soil depth, lithology, or geophysicochemical properties (including pH, moisture content, and grain size) inherently subject to each location. Particularly, the slightly acidic (pH < 6) and low-fertility soil with a higher level of radon concentration exceeding 3000 Bq/m³ had a considerably low level of bacterial density. In contrast, the fertile soil of a relatively middle level of radon radioactivity revealed a much larger bacterial community density, dominated by Bacillus spp., Pseudomonas sp., Paenarthrobacter sp., and Microbacterium sp. Furthermore, the monitored metabolic activity and growth of Bacillus pumilus against the various radon exposure conditions clearly indicated that radon could be considered as the potential ecological risk to natural environmental habitats of microbial soil biota.

Heat-air-moisture coupled model for radon migration in a porous media

Radon is one of the main causes of environmental pollution and lung cancer. The precipitation of radon from porous media is affected by the coupling of heat and moisture, which has not been considered in the existing knowledge. We present a model for predicting radon migration in porous media. This model combines the heat-air-moisture (HAM) coupling model of porous media with a radon migration model to establish three-dimensional partial differential equations for steady-state radon migration under HAM coupling conditions. The finite element method (FEM) was used to obtain a numerical solution. Experimental verification showed that the model had high calculation accuracy; the calculated maximum relative error did not exceed 15%. The results of the model were compared with the results of a conventional model that does consider the coupling of heat and humidity; the results showed significant differences in the radon concentrations and radon flux distribution curves for the two models. The newly developed model revealed that there is a significant coupling effect between migration and the distribution of the temperature field, the humidity field, and radon flux in unsaturated porous media. The radon exhalation rate on the surface of porous media increases linearly with the increase of permeability. The exhalation rate decreased exponentially with the increase in relative humidity. When the trend of the temperature gradient was consistent with the concentration gradient, the radon exhalation rate decreased linearly with the increase in temperature gradient. We establish a new model to study the radon migration in porous media under the coupling of heat and moisture. The model provides a theoretical basis for an effective and accurate analysis of the impact of radon exhalation on the environment.

Coffee Consumption and Lung Cancer Risk: A Prospective Cohort Study in Khon Kaen Thailand

Background:

Lung cancer is a major cause of cancer death worldwide. The incidence of lung cancer in Thailand increasing, but risk factors are rarely reported.

Objective:

To investigate the effect of coffee consumption on lung cancer in Thai population.

Methods:

Between 1990 and 2001, lifestyle and demographic data were collected from 24,528 participants in the Khon Kaen Cohort Study (KKCS), who were followed through 2016, by linking to the Khon Kaen Population-based Cancer Registry. A total of 12,668 eligible participants (68.8% females, mean age 51.0 years at baseline) having complete datasets (239,488 person-years of follow up with 138 incident cases of lung cancer observed) were analyzed using a multi-variable adjusted Cox proportional hazard models.

Results:

Coffee consumption was associated with reduced risk for lung cancer (adj. HR = 0.54; 95% CI: 0.35-0.84) after adjusting for age and gender. Cigarette smoking (adj. HR = 2.76; 95% CI: 1.32-5.78) and family history of cancer (adj. HR = 1.65; 95% CI: 1.10-2.48) were associated with higher risk.

Conclusion:

This study suggests coffee consumption may be a protective factor for lung cancer in among this cohort.

Development and Characterization of Biocompatible Mannose Functionalized Mesospheres: an Effective Chemotherapeutic Approach for Lung Cancer Targeting

The aim of the present study was to analyze the lung targeting potential of surface engineered mesospheres loaded with doxorubicin hydrochloride (DOX). Gelatin-based DOX encapsulated mesospheres were prepared using a steric stabilization process and surface modified with mannose, using the amino group present on the surface of the mesospheres. Gelatin-DOX-mesospheres (M₁) and gelatin-mannosylated-DOX-mesospheres (M₂) were characterized for particle size, polydispersity index, zeta potential, and % entrapment efficiency which were found respectively 8.7 ± 0.35, 0.671 ± 0.018, 1.74 ± 0.27, and 80.4 ± 1.2 for (M₁) and 9.8 ± 0.41, 0.625 ± 0.010, 0.85 ± 0.11, and 75.1 ± 0.7 for (M₂). Furthermore, the mesospheres were characterized by FTIR, DSC, SEM, and TEM. In vitro drug release study of optimized formulation was carried out using the dialysis tube method. The cumulative percent drug release was found to be 79.2 ± 0.1% and 69.6 ± 0.52% respectively for gelatin-DOX-mesospheres and gelatin-mannosylated-DOX-mesospheres. In vitro cytotoxicity of formulations was determined using xenograft A-549 tumor cell lines. The cytotoxicity recorded as IC₅₀ was more in the case of M₂ compared to M₁. In addition, mesospheres exhibited minimal hemolytic toxicity and appear to be promising for sustained drug delivery of DOX to the lungs. Cytotoxicity assay was conducted on the A-549 cell line. The results revealed that gelatin-mannosylated-DOX-mesospheres were maximally cytotoxic as compared to free DOX as well as gelatin-DOX-mesospheres. The lung's accumulation of drug was measured and found maximum after administration of M₂. It may, therefore, be inferred that gelatin-mannosylated-DOX-mesospheres are capable to carry bioactive(s) and can be used specifically to target the lung cancer with minimal side effects.

An Investigation into Indoor Radon Concentrations in Certified Passive House Homes

The Energy Performance of Buildings Directive (EPBD) has introduced the concept of Nearly Zero Energy Buildings (NZEB) specifying that by 31 December 2020 all new buildings must meet the nearly zero- energy standard, the Passive House standard has emerged as a key enabler for the Nearly Zero Energy Building standard. The combination of Passive House with renewables represents a suitable solution to move to low/zero carbon. The hypothesis in this study is that a certified passive house building with high levels of airtightness with a balanced mechanical ventilation with heat recovery (MVHR) should yield lower indoor radon concentrations. This article presents results and analysis of measured radon levels in a total of 97 certified passive house dwellings using CR-39³ alpha track diffusion radon gas detectors. The results support the hypothesis that certified passive house buildings present lower radon levels. A striking observation to emerge from the data shows a difference in radon distribution between upstairs and downstairs when compared against regular housing. The study is a first for Ireland and the United Kingdom and it has relevance to a much wider context with the significant growth of the passive house standard globally.

Coastal blue space and depression in older adults

This paper tests whether higher exposure to coastal blue space is associated with lower risk of depression using data from The Irish Longitudinal Study on Ageing (TILDA), a nationally representative longitudinal study of people aged fifty and over in Ireland. We contribute to the literature on blue space and health by (i) using scores from the Center for Epidemiologic Studies Depression Scale (CES-D) to measure depression outcomes (ii) using new measures of coastal blue space visibility (iii) studying the association in an older population (iv) using data from Ireland. Our results indicate that exposure to coastal blue space is associated with beneficial mental health outcomes: TILDA respondents with the highest share of sea view visibility have lower depression (CES-D) scores, while distance from coastline is not statistically significant when views and proximity are both included in the model. This finding supports the idea that the primary channel through which coastal blue space operates to reduce depression scores is visual rather than related to physical proximity.