Estimation of populations exposed to road traffic noise in districts of Seoul metropolitan area of Korea

Geographical Information System-Aided Noise Pollution Mapping of Urban Puducherry, South India

Context

Noise pollution and its influence on environmental and quality of human life are a major concern and hot topic of scientific research in the twenty-first century.

Aims

Spatial analysis of noise pollution in urban Puducherry, South India.

Settings and Design

Cross-sectional study conducted in 36 locations of urban Puducherry.

Methods and Material

Noise measurements were taken using a calibrated NOR 132 digital sound level meter using the prescribed parameters set by the Central Pollution Control Board. Geo coordinates were taken using Garmin Oregon 550 GPS. Noise measurements were classified according to the Bureau of Indian Standards for town planning into five zones.

Statistical Analysis Used

Noise pollution map of urban Puducherry for three time points of the day was generated using ArcGIS Desktop v10.3 with Geo-statistical module and Inverse Distance method.

Results

Seventeen percent of the sites are high noise sources (80-90 dB), two thirds (65%) of the study sites fall into concentrated average noise zones (70-80 dB), and less than one fifth (18%) of the study sites are in relatively quiet zones across different measurement time slots.

Conclusions

Long-term strategy for noise control should be incorporated in the development of new townships and other infrastructures in accordance with the noise control norms. Implications for future research include monitoring noise pollution levels in rural areas and health effects of noise pollution in bystanders and drivers.

Economic valuation of noise pollution control policy: does the type of noise matter?

As the average noise level and number of noise sources have increased, governments have taken various measures to make soundscapes sustainable. Wise policy decisions require information about the monetary value of noise-control policies. This study elicited people's willingness to pay (WTP) for noise policies, separating traffic noise from residential noise to compare the value of controlling different types of noise. The contingent valuation method was used for the empirical analysis, with data from South Korea. The results show that the monthly mean WTP of respondents was KRW 3392.3 for residential noise reduction and KRW 3507.1 for transport noise reduction; thus, the WTP for the latter is slightly higher than that for the former. Moreover, about 80% of people are unwilling to pay for a noise policy at all, and that high ratio of people with zero WTP must be taken into consideration in the process of policy formulation and implementation. Respondents' experiential and psychological factors were found to be more important than their demographics in explaining their WTP for a noise policy. Potential policy implications based on the analysis results are provided.

The Public Health Impact of Road-Traffic Noise in a Highly-Populated City, Republic of Korea: Annoyance and Sleep Disturbance

Sustainable transportation is an essential part of a sustainable city; however, modern transportation systems with internal-combustion engines emits unacceptably high level of air-pollutants and noise. It is recognized widely that road-traffic noise has negative health impacts (such as annoyance and sleep disturbance) on exposed population in highly-populated cities. These harmful effects should be removed or at least reduced to guarantee the sustainability of modern cities. The estimation of pollutant levels at a specific location and the extent of the damage is therefore important for policy makers. This study presents a procedure to determine the levels of road-traffic noise at both day and night, and an assessment of the adverse health effects across Gwangju Metropolitan City (GMC), Republic of Korea (ROK). Road-traffic noise maps in 2-D and 3-D were generated, in order to find spatial distribution of noise levels across the city and noise level at the façade of a building-floor, respectively. The adoption of existing assessment models for the highly-annoyed (%HA) and highly-sleep-disturbed (%HSD) leads to building-based estimation of the affected population and spatial distribution of the road networks of the city. Very high noise levels were found to exist along major roads in the day and at night, with little difference between them. As a result, approximately 10% and 5% of the total population (n = 1,471,944) were estimated to experience high-level annoyance and sleep disturbance, respectively.

Low Income as a Vulnerable Factor to the Effect of Noise on Insomnia

OBJECTIVE

The present study aimed to examine the potential mediating effect of income level on the association between noise exposure and insomnia.

METHODS

706 individuals were evaluated in conjunction with 2014 noise map data from Seoul, South Korea. Cross-sectional analysis was performed to examine differences in noise level according to household income, while three separate logistic regression models were used to examine factors influencing insomnia. Odds ratios (ORs) were calculated after adjusting for depression, anxiety, auditory acuity and noise sensitivity in the first model. Analyses were adjusted for sociodemographic variables in the second model, lifestyle factors and medical illnesses in the third model.

RESULTS

Noise level was significantly associated with an increased risk of insomnia in the low-income group, although no such association was observed in the high-income group. Groups exposed to >60 dB of noise (Lden; day-evening-night equivalent) exhibited a 1.79-fold increase in the incidence of insomnia relative to those exposed to <50 dB. The result was significant after adjusting sociodemographic variables, although not significant when adjusted for lifestyle factors and medical illnesses.

CONCLUSION

Individuals with low income may be more vulnerable to the deleterious effects of noise exposure on health. Various aspects including income should be considered to ascertain the influence of noise on insomnia.

A simplified sampling procedure for the estimation of methane emission in rice fields

Manual closed chamber methods are widely used for CH₄ measurement from rice paddies. Despite diurnal and seasonal variations in CH₄ emissions, fixed sampling times, usually during the day, are used. Here, we monitored CH₄ emission from rice paddies for one complete rice-growing season. Daytime CH₄ emission increased from 0800 h, and maximal emission was observed at 1200 h. Daily averaged CH₄ flux increased during plant growth or fertilizer application and decreased upon drainage of plants. CH₄ measurement results were linearly interpolated and matched with the daily averaged CH₄ emission calculated from the measured results. The time when daily averaged emission and the interpolated CH₄ curve coincided during the daytime was largely invariant within each of the five distinctive periods. One-hourly sampling during each of these five periods was utilized to estimate the emission during each period, and we found that five one-hourly samples during the season accurately reflected the CH₄ emission calculated based on all 136 hourly samples. This new sampling scheme is simple and more efficient than current sampling practices. Previously reported sampling schemes yielded estimates 9 to 32% higher than the measured CH₄ emission, while our suggested scheme yielded an estimate that was only 5% different from that based on all 136-h samples. The sampling scheme proposed in this study can be used in rice paddy fields in Korea and extended worldwide to countries that use similar farming practices. This sampling scheme will help in producing more accurate global methane budget from rice paddy fields.

Opportunities for Environmental Noise Mapping in Saudi Arabia: A Case of Traffic Noise Annoyance in an Urban Area in Jeddah City

As the traffic and other environmental noise generating activities are growing in The Kingdom of Saudi Arabia (KSA), adverse health and other impacts are expected to develop. The management of such problem involves many actions, of which noise mapping has been proven to be a helpful approach. The objective of the current study was to test the adequacy of the available data in KSA municipalities for generating urban noise maps and to verify the applicability of available environmental noise mapping and noise annoyance models for KSA. Therefore, noise maps were produced for Al-Fayha District in Jeddah City, KSA using commercially available noise mapping software and applying the French national computation method “NMPB” for traffic noise. Most of the data required for traffic noise prediction and annoyance analysis were available, either in the Municipality GIS department or in other governmental authorities. The predicted noise levels during the three time periods, i.e., daytime, evening, and nighttime, were found higher than the maximum recommended levels established in KSA environmental noise standards. Annoyance analysis revealed that high percentages of the District inhabitants were highly annoyed, depending on the type of planning zone and period of interest. These results reflect the urgent need to consider environmental noise reduction in KSA national plans. The accuracy of the predicted noise levels and the availability of most of the necessary data should encourage further studies on the use of noise mapping as part of noise reduction plans.

Analysis of Sampling Methodologies for Noise Pollution Assessment and the Impact on the Population

Today, noise pollution is an increasing environmental stressor. Noise maps are recognised as the main tool for assessing and managing environmental noise, but their accuracy largely depends on the sampling method used. The sampling methods most commonly used by different researchers (grid, legislative road types and categorisation methods) were analysed and compared using the city of Talca (Chile) as a test case. The results show that the stratification of sound values in road categories has a significantly lower prediction error and a higher capacity for discrimination and prediction than in the legislative road types used by the Ministry of Transport and Telecommunications in Chile. Also, the use of one or another method implies significant differences in the assessment of population exposure to noise pollution. Thus, the selection of a suitable method for performing noise maps through measurements is essential to achieve an accurate assessment of the impact of noise pollution on the population.