Real-time emission characteristics, health risks, and olfactory effects of VOCs released from soil disturbance during the remediation of an abandoned chemical pesticide industrial site

Development of a Novel Low-Cost Automated Flux Chamber for Real-Time Monitoring of VOCs Emissions at Contaminated Sites

This study introduces an innovative, low-cost static flux chamber for real-time monitoring of volatile organic compound (VOC) emissions at contaminated sites. Compared to traditional static flux chambers, the developed system is fully automated, eliminating the need for continuous operator intervention in the field. The cylindrical stainless-steel chamber (6.28 L) is equipped with internal sensors for temperature, pressure, and humidity, and a low-cost PID sensor for VOC detection (0.001-40 ppm). VOC flux is determined over 10 min measurement cycles, with two micro diaphragm pumps purging the chamber to reset concentrations. An Arduino Uno microcontroller manages the system, enabling local data storage (SD card) and a LoRa module to send real-time data to the cloud using IoT systems. Powered by a 12 V battery, rechargeable via a photovoltaic panel, the system ensures continuous operation. The prototype costs less than 1.5 k€, significantly cheaper than commercial devices. Accuracy and repeatability were assessed through lab-scale emission tests under dynamic conditions using various aliphatic and aromatic VOCs. Results closely matched those from a commercial gas analyzer and a Comsol Multiphysics numerical model, confirming the system reliability. These findings support its potential as a cost-effective alternative for continuous VOC monitoring at contaminated sites.

Environmental dynamics of pesticides: sources, impacts on amphibians, nanoparticles, and endophytic microorganism remediation

Pesticides, which are widely used in agriculture, have elicited notable environmental concern because they persist and may be toxic. The environmental dynamics of pesticides were reviewed with a focus on their sources, impacts on amphibians, and imminent remediation options. Pesticides are directly applied in ecosystems, run off into water bodies, are deposited in the atmosphere, and often accumulate in the soil and water bodies. Pesticide exposure is particularly problematic for amphibians, which are sensitive indicators of the environment's health and suffer from physiological, behavioral, and developmental disruption that has "pushed them to the brink of extinction." Finally, this review discusses the nanoparticles that can be used to tackle pesticide pollution. However, nanoparticles with large surface areas and reactivity have the potential to degrade or adsorb pesticide residues during sustainable remediation processes. Symbiotic microbes living inside plants, known as endophytic microorganisms, can detoxify pesticides. Reducing pesticide bioavailability improves plant resilience by increasing the number of metabolizing microorganisms. Synergy between nanoparticle technology and endophytic microorganisms can mitigate pesticide contamination. Results show that Interdisciplinary research is necessary to improve the application of these strategies to minimize the ecological risk of pesticides. Eco-friendly remediation techniques that promote sustainable agricultural practices, while protecting amphibian populations and ecosystem health, have advanced our understanding of pesticide dynamics.

Emission characteristics, environmental impacts and health risk assessment of volatile organic compounds from the typical chemical industry in China

To study the volatile organic compounds (VOCs) emission characteristics of industrial enterprises in China, 6 typical chemical industries in Yuncheng City were selected as research objects, including the modern coal chemical industry (MCC), pharmaceutical industry (PM), pesticide industry (PE), coking industry (CO) and organic chemical industry (OC). The chemical composition of 91 VOCs was quantitatively analyzed. The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m3. Alkanes were the main emission components of MCC (62.0%), PE (55.1%), and OC (58.5%). Alkenes (46.5%) were important components of PM, followed by alkanes (23.8%) and oxygenated volatile organic compounds (OVOCs) (21.2%). Halocarbons (8.6%-71.1%), OVOCs (9.7%-37.6%) and alkanes (11.2%-27.0%) were characteristic components of CO. The largest contributor to OFP was alkenes (0.6%-81.7%), followed by alkanes (9.3%-45.9%), and the lowest one was alkyne (0%-0.5%). Aromatics (66.9%-85.4%) were the largest contributing components to SOA generation, followed by alkanes (2.6%-28.5%), and the lowest one was alkenes (0%-4.1%). Ethylene and BTEX were the key active species in various chemical industries. The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work, and BTEX and dichloromethane were the largest contributors.

Appropriate control measure design by rapidly identifying risk areas of volatile organic compounds during the remediation excavation at an organic contaminated site

Many organic contaminated sites require on-site remediation; excavation remediation processes can release many volatile organic compounds (VOCs) which are key atmospheric pollutants. It is therefore important to rapidly identify VOCs during excavation and map their risk areas for human health protection. In this study, we developed a rapid analysis and assessment method, aiming to and reveal the real-time distribution of VOCs, evaluate their human health risks by quantitative models, and design appropriate control measures. Through on-site diagonal distribution sampling and analysis, VOCs concentration showed a decreasing trend within 5 m from the excavation point and then increased after 5 m with the increase in distance from the excavation point (p < 0.05). The concentrations of VOCs near the dominant wind direction were higher than the concentrations of surrounding pollutants. In contrast with conventional solid-phase adsorption (SPA) and thermal desorption gas chromatography-mass spectrometry (TD-GC/MS) methods for determining the composition and concentration of VOCs, the rapid measurement of VOCs by photo-ionization detector (PID) fitted well with the chemical analysis and modeling assessment of cancer/non-cancer risk. The targeting area was assessed as mild-risk (PID < 10 ppm), moderate-risk (PID from 10 to 40 ppm), and heavy-risk (PID > 40 ppm) areas. Similarly, the human health risks also decreased gradually with the distance from the excavation point, with the main risk area located in the dominant wind direction. The results of rapid PID assessment were comparable to conventional risk evaluation, demonstrating its feasibility in rapidly identifying VOCs releases and assessing the human health risks. This study also suggested appropriate control measures that are important guidance for personal protection during the remediation excavation process.