In situ monitoring of chlorothalonil and lambda-cyhalothrin by polyethylene passive samplers under fields and greenhouse conditions.

Sampling is a critical step in pesticide atmospheric analysis. Passive sampling offers advantages of inexpensive and convenient air monitoring. Polyethylene films (PE) were used as a passive sampler at multiple heights in greenhouse and agricultural field for 15 days to trap atmospheric chlorothalonil and lambda-cyhalothrin in the months of May and July. Among the two PE film thicknesses (20 and 80 µm), 20 µm PE was the most effective at absorbing target pesticides from air and attains equilibrium stage earlier than 80 µm PE film. After approximately 240 h of PE exposure in greenhouse and fields, chlorothalonil and lambda-cyhalothrin reached an equilibrium stage of partitioning between air and PE. Atmospheric concentrations of chlorothalonil (p < 0.01) and lambda-cyhalothrin (p < 0.001) at 1.5 m height were higher with the concentrations of 1855.59 ± 243.85 ng/m3 and 3682.11 ± 316.71 ng/m3, respectively, in the month of May as compared to the other three respective heights. The concentrations of chlorothalonil in air at 2 m height (1587.27 ± 284.19 ng/m3) were slightly higher than 0.5 m (1392.28 ± 205.09 ng/m3). Atmospheric concentrations of lambda-cyhalothrin at 2 m (3178.26 ± 299.29 ng/m3) were significantly lower than the other heights (p < 0.05). The greenhouse air concentrations of chlorothalonil and lambda-cyhalothrin in the months of May (1855.59 ± 243.85 and 3682.11 ± 316.71 ng/m3, respectively) and July (1749.33 ± 378.61 and 3445.08 ± 390.32 ng/m3, respectively) were higher than fields. The results indicate the usability of PE films to monitor chlorothalonil and lambda-cyhalothrin and potential other semi-volatile pesticides in agricultural fields.

Valuing and significance of eco-tourism parks across eastern arid regions of Pakistan.

The green spaces preserve natural heritage, spectacular landscapes, and wildlife habitats. By incorporating national parks, it leads to economic growth, environmental sustainability, social involvement, and provides a protected area for endangered wildlife. Nature-dependent tourism indicates a critical place within the national economy. Pakistan is tackling the tourism industry and implementing nature-related approaches using national parks. The main objective of the proposed study is to appraise the economic value of the eastern arid regions of Pakistan and determine their environmental importance. For the assessment of recreational value, the travel cost method (TCM) and the zero truncated negative binomial regression models were chosen. Recreation demand was negatively linked to salary and had a significant positive association with the place of residence, age, and length of stay. The total estimated annual consumer surplus of the parks was Rs. 3317/person, while outsider consumer surplus was Rs. 3032/person/visit, and consumer surplus native annual value was Rs. 3289/person/visit. The results show that visitors have fewer tendencies towards the recreational site, as they are restricted to paying the entrance fee. This study contributes to environmental content reservations, such as a clean atmosphere, soil protection, and a stable ecosystem. It also improves economic valuation and sends a thought-provoking signal to native authorities to effectively manage the supervision of national parks.