Arsenic contribution of poultry manure towards soils and food plants contamination and associated cancer risk in Khyber Pakhtunkhwa, Pakistan.

Exposure to high level of arsenic (As) through the ingestion of contaminated soil, dust and food plants can pose health risk to humans. This study investigates the total arsenic (As), arsenobetaine (AsB), monomethylarsenate (MMA), dimethylarsenate (DMA), arsenite (As3+) and arsenate (As5+) concentrations in poultry feed, manure, agricultural soils and food plants collected from Khyber Pakhtunkhwa Province, Pakistan. The total mean As concentrations in the edible parts of food plants ranged from 0.096 mg kg-1 to 1.25 mg kg-1 with percentile (P) values (P25-0.039, P50-0.0765, P75-0.165 1 mg kg-1 to P25-0.95, P50-1.23, P75-1.6 1 mg kg-1) and exceeded the food safety limit (0.1 mg kg-1) of Food & Agriculture Organization (FAO) and World Health Organization (WHO) in all plant species except Pisum sativum (pea) and Mentha arvensis (mint). The risk to human health was assessed through the average daily intake (ADI), hazards quotient (HQ), health risk index (HRI) and lifetime cancer risk (LTCR). The highest average daily intake of As via the ingestion of Malva neglecta (mallow, a leafy plant) was observed for adults and children. The ADI for adults and children (2.36 × 10-4 mg kg-1 day-1 and 6.33 × 10-4 mg kg-1 day-1) was about 13% and 5%, respectively, of the Bench Mark Dose Limit (BMDL0.5) of 3.00 × 10-3 mg kg-1 day-1 set by WHO. The HRI was 3 times more in the children (2.1) than the adults (0.79), posing non-cancer health risks (health risk index > 1) for children. The LTCR values were slightly higher (1.53 × 10-4) relative to USEPA and WHO limits (1 × 10-6 to 1 × 10-4) for children whereas a minimal cancer risk was observed for adults via consumption of selected food plants. The results showed that poultry manure can contaminate food plants that may lead to cancer and non-cancer risks in agricultural areas, Pakistan. Thus, it is important to minimize As concentration in poultry feed to safeguard human health and environment from adverse effects.

Temporal and seasonal variations of noise pollution in urban zones: a case study in Pakistan.

Noise pollution is widely recognized as an important problem and can negatively affect quality of life. This study aimed to examine the temporal and seasonal variations of noise pollution in urban zones of Peshawar, Pakistan. This city is increasingly becoming congested and traffic-related problems are common. Noise levels were assessed in four different seasons at 20 points around the city, including three different zones: commercial, residential, and silent. All the noise indices including equivalent noise level, day and night time noise level, noise climate, and noise pollution level were calculated for all zones. In winter, the Leq values ranged between 52.5 and 73.3 dBA; while in spring, summer, and autumn, it ranged between 56.2 and 88.3 dBA; 46.9 and 88.6 dBA; and 49.2 and 76.6 dBA, respectively. The level of the noise was observed highest in commercial followed by residential and the silent zones. The levels of the noise were beyond the permissible limits in some zones mentioned in the Pakistan National Environmental Quality Standards (Pak-NEQS' 2010). The seasonal variation in Leq revealed that the noise level in 70% of areas increased from winter to spring, 45% from spring to summer, 35% summer to autumn, 30% autumn to winter, 70% winter to summer, and 40% spring to autumn. Temperature, humidity, and wind speed were the main seasonal factors causing the seasonal variations and traffic was the main source of noise pollution identified in the area.

Effects of ozone phytotoxicity in reducing the yield and nutritional quality of chilli (Capsicum annuum L.).

This study was designed to assess the effects of tropospheric ozone (O3) on the yield and nutritional quality of chilli (Capsicum annuum L. cv. Pusa Jwala) using ethylene diurea (EDU) under field conditions in Peshawar, Pakistan. Average O3 concentration ranged between 38 and 68 ppb which is high enough to cause phytotoxic effects. Accumulated ozone exposure over a threshold of 40 ppm h (AOT40) value calculated for 3-month period was found to be substantially higher, i.e., 7.3 ppm h. Various growth and yield parameters analyzed on weekly basis showed that the plant height (6.3%), number of flowers (15%), fruits (36%), and total dry biomass (30%) and its nutritional quality parameters such as mean crude protein, fat, and fiber showed 24%, 100%, and 12% better results in EDU-treated plants as compared with control, respectively. However, mineral contents showed no significant difference (p < 0.05) for both the groups. The results of this study concluded that ambient O3 is a threat to the selected plant species thus affecting its quality and yield and EDU remains successful in protecting the chilli (Capsicum annuum L.) against the negative effects of tropospheric ozone.

Assessment of noise pollution and associated subjective health complaints and psychological symptoms: analysis through structure equation model.

Road traffic noise is affecting the exposed population through its detrimental effects. This study was conducted in urban zones of Peshawar, Khyber Pakhtunkhwa, Pakistan, to analyze causal relationship between noise and subjective health complaints with a special focus on psychological symptoms. A 12-h (LAeq) noise survey conducted at different locations (n = 57) indicated a noise range of 46.3-86.3 dB (A). A questionnaire survey was conducted from local residents (n = 500), students (n = 500), policemen (n = 500), shopkeepers (n = 500), and drivers (n = 500) exposed to road traffic noise and analyzed through structure equation modeling (SEM). Different models were prepared and a modified model obtained the acceptable model fit, i.e., chi-square 0.093, χ2/df 1.286, comparative fit index 0.986, goodness of fit index 0.966, normed fit index 0.943, Tucker-Lewis index 0.977, and root mean square error of approximation 0.034. The modified model gives not only the information about direct but also indirect effects of noise on the exposed population. Adding on, the model clearly indicates that sensitivity to noise has strong relationship with subjective health complaints (headache, exhaustion, and psychological symptoms such as annoyance, difficulty concentrating, ill temper, and anxiety) than profession, age, location, and gender. Duration of exposure to road traffic noise has an important role in increasing the frequency of subjective health issues. The model is important in depicting that sensitivity to noise may produce subjective health complaints (standardized parameter estimates of 0.12 and 0.29) but the mediator has much stronger positive path estimates (0.59). The modified model sought to discover and explicate the underlying mechanism of an observed relationship existing between the selected dependent and an independent variable through the identification of the mediator variables.