ABSTRACT
Heavy metal bioaccumulation in organisms is primarily a result of dietary uptake. The current study examines the concentrations of heavy metals (Pb, Cd, Cr, and Cu) in fish feed, water, sediment, and three fish species (Catla catla, Labeo rohita, and Cyprinus carpio) from different feeding zones in a polyculture pond system. Furthermore, associated human health risks were also evaluated. The fish samples (n = 25 for each species) were collected from 10 different fish ponds in the Kohat district, Pakistan. Heavy metals were determined using an atomic absorption spectrometer. Results revealed higher concentrations of heavy metals in sediment, followed by water. However, the concentration of heavy metals in fish feed was lower than the standard limits. In the case of fish, the bottom feeder (C. carpio) notably exhibited higher (P < 0.05) levels of heavy metals than the column feeder (L. rohita) and surface feeder (C. catla) fish. Moreover, in the liver of all fish species, the bioaccumulation of heavy metals was higher, followed by the gills. Principal component analysis (PCA) demonstrated a strong correlation of heavy metals in C. carpio gills, flesh, feed, and pond water, while the heavy metals in the liver correlated with the detected metals in sediment. The human health risk analysis shows that bottom feeder fish had higher estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) values (> 1). Consequently, the exposed population may experience adverse health effects. The findings of this study suggest that the bottom feeder (C. carpio) bioaccumulates a higher concentration of heavy metals than column (L. rohita) and surface feeder (C. catla) in the polyculture system.
ABSTRACT
BACKGROUND: The current coronavirus disease 2019 (COVID-19) pandemic continues with resurgent second and third waves worldwide. Vaccination is one of several measures that are needed to end this pervasive threat. Pakistan, however, has a relatively low rate of routine vaccine acceptance. Our study aimed to determine the proportion and predictors of COVID-19 vaccine hesitancy (VH) among adults in Pakistan. METHODS: An online cross-sectional study was conducted from December 27, 2020 to March 6, 2021. Non-probability sampling was applied to recruit study participants through social media platforms (ie, Facebook and Twitter) and through free messaging services (WhatsApp). Stata 16 was used to generate descriptive statistics and logistic regression models for identifying predictive variables of vaccine hesitancy. A p-value of <0.05 was considered strong evidence against the null hypothesis. RESULTS: Out of 1014 participants, 35.8% (n=363) were hesitant about receiving the COVID-19 vaccine. Reasons for VH included concerns about side effects (42.4%), belief in conspiracy theories (20.1%), perceived inefficacy of the vaccine (13.2%), and perceived protection through precautionary measures (12.6%). Urban residency (AOR 2.34, 95% CI 1.54-3.57), reservations about vaccine safety (AOR 3.29, 95% CI 1.68-6.44), uncertainty about vaccine efficacy (AOR 2.70, 95% CI 1.50-4.86), failure of the vaccine to reduce hospitalization and death (AOR 6.36, 95% CI 4.01-10.22), and unfelt need for vaccination awareness among public (AOR 2.02, 95% CI 1.28-3.14) were associated with higher rates of VH. At least one chronic disease (AOR 0.60, 95% CI 0.39-0.92), knowing someone infected with COVID-19 (AOR 0.56, 95% CI 0.39-0.81), and trusting information from the ministry of health (AOR 0.64, 95% CI 0.41-0.99) and physicians (AOR 0.27, 95% CI 0.13-0.53) were found to be associated with lower rates of COVID-19 VH. CONCLUSION: More than one third of survey participants were VH. COVID-19 vaccine uptake in Pakistan can be improved through targeted health education strategies and planned interventions that address the barriers identified in the present study.
