Herein, the catalytic properties of a carbonaceous nanocomposite in the catalytic ozonation process (COP) of 2, 4-dinitrophenol (2, 4-DNP) were investigated and the results were compared with those obtained from single ozonation process (SOP). Magnetic carbonaceous nanocomposite, as a novel catalyst, was applied to optimize the condition for the removal of 2, 4-DNP in the COP, and the influential parameters such as pH, catalyst dosage, addition of radical scavengers, and durability were all evaluated. The results showed that the degradation efficiency of 2, 4-DNP and COD in the COP (98.2, 92%) was higher compared to the SOP (75, 61%) and the highest catalytic potential was achieved at an optimal pH of 6. The first-order modeling demonstrated that the reactions were dependent on the concentration of the catalyst, with the kinetic constants varying from 0.022 (1/min) in the SOP to 1.377 (1/min) in the COP at the catalyst dosage of 4 g/L and the optimum concentration of catalyst (2 g/L). The addition of radical scavenger noticeably diminished the removal efficiency of 2, 4-DNP in the SOP from 75% down to 54%, while the corresponding values for the COP dropped from 98.2 to 93%. Furthermore, a negligible reduction in the catalytic properties of the catalyst was observed (~5%) after five-time reuse. The results also revealed that the applied method is effectively suitable for the removal of 2, 4-DNP contaminant from industrial wastewaters.

A new strategy in catalytic ozonation removal method for degradation and detoxification of phenol from industrial wastewater was investigated. Magnetic carbon nanocomposite, as a novel catalyst, was synthesized and then used in the catalytic ozonation process (COP) and the effects of operational conditions such as initial pH, reaction time, and initial concentration of phenol on the degradation efficiency and the toxicity assay have been investigated. The results showed that the highest catalytic potential was achieved at optimal neutral pH and the removal efficiency of phenol and COD is 98.5% and 69.8%, respectively. First-order modeling demonstrated that the reactions were dependent on the initial concentration of phenol, with kinetic constants varying from 0.038 min⁻¹ ([phenol]_o= 1500 mg/L) to 1.273 min⁻¹([phenol]_o= 50 mg/L). Bioassay analysis showed that phenol was highly toxic toDaphnia magna(LC₅₀96 h=5.6 mg/L). Comparison of toxicity units (TU) of row wastewater (36.01) and the treated effluent showed that TU value, after slightly increasing in the first steps of ozonation for construction of more toxic intermediates, severely reduced at the end of reaction (2.23). Thus, COP was able to effectively remove the toxicity of intermediates which were formed during the chemical oxidation of phenolic wastewaters.

Background: Crystal (methamphetamine) is a strong stimulant of addictive substances that affects the central nervous system. The consumption of this substance is increasing among teenagers and adult young people in the country. In this matter, one of the practical and important ways to its control is to identify the factors leading to its first use. Thus this paper, explores the factors related to the first crystal use in Golestan province, Iran. Methods: In a qualitative study, 19 crystal users were recruited in the study conducted in Golestan province by snowball sampling from DIC (Drop-In Center) in addiction treatment centers. The interviews were mostly carried out individually with the participants; only one interview was conducted in an addiction treatment camp in the form of a group-focused discussion. Data analysis was implemented through content analysis in MAXQDA 10 software. Results: The mean age of the participants was 35.05 ± 6.06 years with a range of 23–46 years. Meanwhile, the mean of crystal use period was 7.42 (SD: 3.61) and a range of 1–14 years. Based on the obtained data, the reasons for first crystal use could be categorized in six; 1: “crystal use to other drugs rehabilitation”; 2: “Lack of awareness of the addictive nature of crystal”; 3: “stimulating curiosity in public with crystal-use friends”, 4: affordable and convenient use”, 5: “anti-sleeping effects and increasing work efficiency”, and 6: “therapeutic and other misconceptions”“. Conclusions: The results indicated that crystal is mostly abused to opium rehabilitation. The lack of awareness and misconceptions about this substance can lead people to crystal use. Therefore, designing public health interventions to increase awareness about negative consequences of crystal use is fundamental to prevent people from abusing it. We suggest designing public health program to promote awareness about health risks of crystal and modifying related misconceptions. Finally, the government can establish policies to mandate sale tax for crystal producers and reduce easy access to crystal especially among youth.

Cigarette smoking causes serious complications and diseases in a person’s life, such as Chronic Obstructive Pulmonary Disease (COPD) and some cancers, including lung cancer. On the other hand, studies have shown that smokers do not have a real understanding of the health hazards of smoking. This study was conducted to determine the perceived risk of lung cancer and COPD in current smokers. This cross-sectional study which was conducted between January-May 2023, recruited 380 current smokers by convenience sampling in community setting. The data were collected face to face using three questionnaires (1) the risk perception for lung cancer and COPD questionnaire, (2) the smoking stage of change questionnaire, and (3) the Fagerström test for nicotine dependence. We examined the relationship between the included variables and the smokers’ perceived risk of lung cancer and COPD by using multiple linear regression. We found that lower education (coefficient = 3.60, 95%CI [1.00, 6.19], P < 0.0001) for elementary level and (coefficient = 2.81, 95% CI [0.36, 5.26], P < 0.05) for secondary level had greater lung cancer perceived risk. Besides, smoking age onset for 20 + years (coefficient=-1.36, 95%CI [-2.42, -3.17], P < 0.0001) lower than those who started before the age of 20 were associated with lower perceived risk for lung cancer. Regarding COPD, results indicated that lower education (coefficient = 4.54, 95% CI [1.87, 7.21], p < 0001) for elementary level (coefficient = 3.35, 95% CI [0.83, 5.87], p < 0.001) for secondary level and (coefficient = 3.03, 95% CI[-0.67, 4.25], P < 0.05) for high school dropout, and employment status (coefficient = 3.62, 95% CI[0.66, 6.59], p < 0.05) of employer and (coefficient = 3.23, 95% CI [0.14, 6.33], p < 0.05) for homemaker reported greater perceived risk. This study’s results showed that participants’ perceived risk was relatively low. It seems necessary to carry out interventions to inform about the harms of smoking and to enhance public awareness about the heightened risks of diseases such as lung cancer and COPD among cigarette smokers.

Hookah consumption is harmful to human health and can cause various diseases. Developing lung cancer and other lung diseases are one of the health consequences of hookah consumption. Measuring the perceived risk for being diagnosed with these conditions among hookah users is necessary. Therefore, this study was conducted to determine the perceived risk of lung cancer and Chronic Obstructive Pulmonary Disease (COPD) in hookah users in Iran. This cross-sectional study was conducted with a descriptive-analytical approach on 340 hookah users between January-May 2023. These people were recruited through convenience sampling. The information on the perceived risk of participants was collected through a questionnaire on the perceived risk of lung cancer and COPD. Data were analyzed through descriptive tests and multiple linear regression tests. These analyses were performed using Stata statistical software version 17. The mean and standard deviation of the perceived risk for lung cancer was 8.41 ± 5.50 and for COPD was 8.51 ± 5.58 out of 20 possible scores. The results of multiple linear regression generally showed that the using other type of tobacco (β = 3.14, p < 0.0001), 2 or more use of hookah in past month (β=-3.41, p = 0.025), unskilled workers (β = 1.79, p = 0.017), married smokers (β=-1.31, p = 0.026), negative attitude toward hookah (β = 0.46, p < 0.0001) were the predictive variables regarding to lung cancer perceived risk. In line with COPD the using other type of tobacco (β = 3.47, p < 0.0001), once a month use of hookah in past month(β=-3.74, p = 0.041) and twice or more use of hookah in past month (β=-4.82, p = 0.008), smokers in contemplation stage (β = 3.91, p < 0.0001), female smokers (β = 3.08, p < 0.0001), unskilled workers (β = 2.42, p = 0.007), negative attitude toward hookah (β = 0.46, p < 0.0001) were the predictive variables to COPD perceived risk. In general, the perceived risk of developing lung cancer and COPD among hookah users was low. Therefore, it is necessary to provide widespread information about the potential harm of hookah in causing lung cancer and COPD, at the community level.