Geospatial analysis for environmental noise mapping: A land use regression approach in a metropolitan city.

Environmental noise can lead to adverse health outcomes. Understanding the spatial variability of environmental noise is crucial for mitigating potential health risks and developing influential urban strategies for reducing noise levels. This study aimed to measure noise levels and develop a land use regression (LUR) model to determine the spatial variability of environmental noise in Shiraz, Iran. A grid-based technique was used to establish 191 noise measurement sites (summer) across the city to generate the LUR model based on two noise metrics: Lden and Lnight. Leave-one-out cross-validation (LOOCV) and 38 additional measurement sites (winter) were used for the LUR model assessment. The mean values of Lden and Lnight during summer were 68.20 (±8.05) and 58.95 (±9.55), respectively, while during winter, the corresponding values were 69.46 (±5.46) and 58.81 (±6.79). The LUR models explained 67% and 65% of the spatial variability in Lden and Lnight, respectively. LOOCV analysis demonstrated R2 values of 0.64 and 0.61. Moreover, findings indicated mean absolute error (MAE) values of 3.96 dB(A) for Lden and 4.74 dB(A) for Lnight. Validation based on an additional set of 38 measurement sites revealed R2 values of 0.62 for both Lden and Lnight, with MAE of 2.78 and 3.31, respectively. In addition, the adjusted R2 values were 0.54 and 0.53. The results indicated no significant temporal variations between summer and winter. The results revealed that road-related variables significantly influenced noise levels. Moreover, the results indicated that Lden and Lnight levels were higher than the World Health Organization recommendations for exposure to road traffic noise. The results of our study showed that the LUR modeling approach based on geographical predictors is an effective tool for assessing changes in ambient noise levels in other cities in Iran and around the globe.

Nitrates in industrial and traditional tomato paste from Arsenjan City, Iran: a health risk assessment study.

A comprehensive approach was used for the first time to measure NO3- risk in tomato paste consumption; besides a robust deterministic and probabilistic method was used. The mean levels of NO3- in homemade and industrial tomato paste were 7.36 mg/kg and 43.69 mg/kg, respectively. The Monte Carlo simulation confirmed that these values were below normal levels (HQ less than 1). The sensitivity analysis displayed that FIR was the main factor affecting the risk to human health in both groups. The interactive plot demonstrated the interaction between C and IR for children and adults in both types of tomato paste. This study concludes that NO3- ingestion due to tomato paste consumption poses no significant health risk. However, considering that food and water constitute the primary sources of NO3- intake, continuous monitoring is recommended due to potential health risks associated with excessive NO3- consumption, including certain forms of cancer.

Health risk assessment of exposure to atrazine in the soil of Shiraz farmlands, Iran.

Atrazine-contaminated soils can pose a carcinogenic and non-carcinogenic health risk through different routes for exposed people. This study aimed to assess the health risk of exposure to atrazine-contaminated soils through direct ingestion and dermal contact in farmlands nearby Shiraz. Atrazine concentration was measured in 22 selected sites using grid sampling. The carcinogenic and non-cancer risks associated with dermal and ingestion exposure in children and adults were estimated. The lowest and highest atrazine concentrations were in S1 (0.015 mg/kg soil) and S22 (0.55 mg/kg soil). Hazard Index (HI)1 values ranged from 0.007 to 0.25 for children, and the values ranged from 0.0008 to 0.03 for adults. The mean cancer risk for children and adults was 6.01 × 10-4 and 7.40 × 10-5, respectively. The HI value was less than 1 for all sampling sites, indicating that exposure to atrazine does not threaten children and adults. However, the cancer risk exceeds the United States Environmental Protection Agency (US.EPA)2 threshold risk limit (10-6 to 10-4) in all sampling sites. Therefore, it is recommended that children should avoid playing on atrazine-contaminated farms or soils near anywhere atrazine may have been used.

Health risks of inhalation exposure to BTEX in a municipal wastewater treatment plant in Middle East city: Shiraz, Iran.

Benzene, toluene, ethylbenzene, and xylene, known as BTEX, adversely affect human health. This study aimed to measure BTEX concentration and assess the health risk through inhalation exposure to these compounds in a municipal wastewater treatment plant. The ambient air samples were collected using the active sampling method in summer and winter. Sampling sites were close to wastewater treatment units, including bar screen & grit chamber (Site-1), aeration tank & secondary clarifiers (Site-2), anaerobic sludge digester (Site-3), and office & control building (Site-4). Results indicate that the mean levels of benzene and toluene in winter were higher than in summer. The levels of benzene and toluene were below the occupational exposure levels of the American Conference of Governmental Industrial Hygienists (ACGIH) and Occupational Safety and Health Administration (OSHA). The carcinogenic risk (CR) and hazard quotient (HQ) were assessed using the United States Environmental Protection Agency (U.S.EPA) method, and Monte Carlo simulation (MCS) was applied to quantify the uncertainty and sensitivity analysis. The CRs for all sampling sites were below the U.S.EPA threshold limit (1.0 × 10-4). The HQ values for benzene nearby Site-2 were above 1.0, indicating inhalation exposure could pose a health hazard. Besides, the HQ results for exposure to toluene in all sampling sites were less than 1.0. The sensitivity analysis had shown that the risk determinant for carcinogenic and non-carcinogenic risk was exposure time, followed by concentration.

Health impact assessment of air pollution in Shiraz, Iran: a two-part study.

We aimed to assess health-impacts of short-term exposure to the air pollutants including PM10, SO2, and NO2 in Shiraz, Iran in a two-part study from 2008 to 2010. In part I, local relative risks (RRs) and baseline incidences (BIs) were calculate using generalized additive models. In part II, we estimated the number of excess hospitalizations (NEHs) due to cardiovascular diseases (CDs), respiratory diseases (RDs), respiratory diseases in elderly group (RDsE-people older than 65 years old), and chronic obstructive pulmonary diseases (COPDs) as a result of exposure to air pollutants using AirQ model, which is proposed approach for air pollution health impact assessment by World Health Organization. In part I, exposure to increase in daily mean concentration of PM10 was associated with hospitalizations due to RDs with a RR of 1.0049 [95% confidence interval (CI), 1.0004 to 1.0110]. In addition, exposure to increase in daily mean concentration of SO2 and NO2 were associated with hospitalizations due to RDsE and COPDs with RRs of 1.0540 [95% CI, 1.0050 to 1.1200], 1.0950 [95% CI, 1.0700 to 1.1100], 1.0280 [95% CI, 1.0110 to 1.0450] and 1.0360 [95% CI, 1.0210 to 1.0510] per 10 µg/m3 rise of these pollutants, respectively. In part II, the maximum NEHs due to CDs because of exposure to PM10 were in 2009-1489 excess cases (ECs). The maximum NEHs due to RDs because of exposure to PM10 were in 2009-1163 ECs. Meanwhile, the maximum NEHs due to RDsE and COPDs because of exposure to SO2 were in 2008, which are 520 and 900 ECs, respectively. In conclusion, elevated morbidity risks were found from acute exposure to air pollutants.