exposure estimation
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2021 ◽  
Author(s):  
Matthew Marcath ◽  
Douglas Mayo ◽  
Joshua Spencer ◽  
Tucker McClanahan ◽  
Lucas Hetrick

2021 ◽  
Author(s):  
Chao-Heng Tseng ◽  
Ling Ling Chen ◽  
Guan-Hua Tseng

Abstract Low-cost air-pollution sensors are attracting increasing attention. They offer air-pollution monitoring at a cost lower than that of conventional methods, theoretically facilitating air-pollution monitoring in several locations and immediate application of acquired information. We establish a particulate matter (PM2.5) map based on low-cost air-pollution sensor information developed using internet of things at Taiwan’s Environmental Protection Agency. We synergize data from one monitoring station with 287 low-cost air-pollution-pollution sensors (data entries = ∼50 million) to estimate PM2.5 concentrations from September 1, 2018 to August 31, 2019. We investigate Chiayi City because it has the second-highest PM2.5 concentration in Taiwan. By analyzing Geographic Information System data, we map Chiayi City’s spatial and temporal distributions, identify PM2.5, and recognize the characteristics of Chiayi City’s hotspots. Our main discoveries are as follows: Chiayi City’s spatial distribution reveals PM2.5 concentrated in its industrial area, which increasingly reduces from the industrial area to the city center. Hot spots are identified by two types of space units: northwest industrial and central and western agricultural zone. Concentrated PM2.5 occurs mainly in winter, with the highest rate in January, occurring most frequently and less frequently from 7 to 10 a.m. and 3 to 5 p.m., respectively. Although this study focuses on Chiayi City, the proposed approach has general applicability to wide-ranging environment-monitoring studies and air-pollution interventions and will substantially assist in validating PM2.5 transport models and enhance exposure estimation accuracy in further research.


2021 ◽  
Vol 9 ◽  
Author(s):  
Dionna J. Green ◽  
Kyunghun Park ◽  
Varsha Bhatt-Mehta ◽  
Donna Snyder ◽  
Gilbert J. Burckart

The regulatory framework for considering the fetal effects of new drugs is limited. This is partially due to the fact that pediatric regulations (21 CFR subpart D) do not apply to the fetus, and only US Health and Human Service (HHS) regulations apply to the fetus. The HHS regulation 45 CFR Part 46 Subpart B limits research approvable by an institutional review board to research where the risk to the fetus is minimal unless the research holds out the prospect of a direct benefit to the fetus or the pregnant woman (45 CFR 46.204). Research that does not meet these requirements, but presents an opportunity to understand, prevent, or alleviate a serious problem affecting the health of pregnant women, fetuses, or neonates, may be permitted by the Secretary of the HHS after expert panel consultation and opportunity for public review and comment (45 CFR 46.407). If the product is regulated by the US Food and Drug Administration (FDA), FDA may get involved in the review process. The FDA does however have a Reviewer Guidance on Evaluating the Risks of Drug Exposure in Human Pregnancies from 2005 and this guidance does discuss the intensity of drug exposure. Estimation of that exposure using physiologically based pharmacokinetic (PBPK) modeling has been suggested by some investigators. Given that drug exposure during pregnancy will impact the fetus, a number of new guidances in the last 2 years also address inclusion of pregnant women in clinical drug trials. Therefore, the drug-specific information on fetal pharmacology will increase dramatically in the next decade due to interest in drugs administered in pregnancy and with the assistance of model-informed drug development.


Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 507
Author(s):  
Matheus Frey ◽  
Roice Rosim ◽  
Carlos Oliveira

The aim of this study was to conduct a first evaluation on the co-occurrence of aflatoxins (AF) M1, B1, B2, G1 and G2; fumonisins (F) B1 and B2; deoxynivalenol (DON); de-epoxydeoxinivalenol (DOM-1); ochratoxin A (OTA); zearalenone (ZEN); α-zearalenol (α-ZEL); and β-zearalenol (β-ZEL) in 68 samples of fluid milk consumed in Pirassununga, São Paulo, Brazil. The probable daily intake (PDI) was also calculated for each mycotoxin evaluated. Mycotoxins were determined by liquid chromatography coupled to mass spectrometry. Sixty-two (91.2%) samples contained at least one type of mycotoxin. AFM1 was found in 6 samples (8.8%), and none of them presented concentrations above the Brazilian maximum permitted level in milk (500 ng/L). Low levels of non-regulated mycotoxins DOM-1, OTA, FB1, FB2, α-ZEL and β-ZEL were found in 6 (8.8%), 17 (25%), 10 (14.7%), 3 (4.4%), 39 (57.4%) and 28 (41.2%) samples of milk, respectively. None of the PDIs calculated for the quantified mycotoxins were above recommended values, indicating low exposure through milk consumption in the area studied. However, 21 samples (30.9%) contained 2–4 types of mycotoxins, which warrants concern about the potential adverse effects of mycotoxin mixtures in milks.


Toxics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 155
Author(s):  
Clara Amalie Gade Timmermann ◽  
Signe Sonne Mølck ◽  
Manik Kadawathagedara ◽  
Anne Ahrendt Bjerregaard ◽  
Margareta Törnqvist ◽  
...  

The dietary intake of acrylamide (AA) is a health concern, and food is being monitored worldwide, but the extent of AA exposure from the diet is uncertain. The aim of this review was to provide an overview of estimated dietary intake. We performed a PubMed search identifying studies that used dietary questionnaires and recalls to estimate total dietary AA intake. A total of 101 studies were included, corresponding to 68 original study populations from 26 countries. Questionnaires were used in 57 studies, dietary recalls were used in 33 studies, and 11 studies used both methods. The estimated median AA intake ranged from 0.02 to 1.53 μg/kg body weight/day between studies. Children were represented in 25 studies, and the body-weight-adjusted estimated AA intake was up to three times higher for children than adults. The majority of studies were from Europe (n = 65), Asia (n = 17), and the USA (n = 12). Studies from Asia generally estimated lower intakes than studies from Europe and the USA. Differences in methods undermine direct comparison across studies. The assessment of AA intake through dietary questionnaires and recalls has limitations. The integration of these methods with the analysis of validated biomarkers of exposure/internal dose would improve the accuracy of dietary AA intake exposure estimation. This overview shows that AA exposure is widespread and the large variation across and within populations shows a potential for reduced intake among those with the highest exposure.


2021 ◽  
Vol 279 ◽  
pp. 116938
Author(s):  
Carolina F.S.C. Coppa ◽  
Amanda C. Cirelli ◽  
Bruna L. Gonçalves ◽  
Eliana M.B. Barnabé ◽  
Tânia Petta ◽  
...  

2021 ◽  
Vol 67 (2) ◽  
pp. 3402-3420
Author(s):  
Kata Kerekes ◽  
Szilveszter Csorba ◽  
Árpád Ambrus

The mycotoxin contamination of foods also appears in the food chain. Aflatoxin is metabolized in animals and its aflatoxin M1 (AFM1) metabolite, which is similarly, but ten times less genotoxic and carcinogenic than aflatoxin B1 (AFB1), is also present in milk, liver and eggs. Of these, the most significant food safety risk is posed by the contamination of milk with AFM1. In our article, the deterministic exposure estimation of Hungarian consumers is presented, based on the AFM1 contamination of milk and dairy products. The results indicate that the exposure of children under three years of age clearly poses a health risk, while the exposure of the 3 to 6 year old age group is borderline. The exposure of older age groups in ng/kg body weight does not pose an immediate health risk due to the increasing body weight. However, it needs to be emphasized that the presence of carcinogenic compounds should be kept to a minimum in all age groups. To this end, we propose an amendment to the regulation regarding the factory inspection of milk.


Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2546
Author(s):  
Rikke Bramming Jørgensen ◽  
Ida Teresia Kero ◽  
Aleksander Blom ◽  
Esten Eide Grove ◽  
Kristin von Hirsch Svendsen

Background: It is difficult to assess workers’ exposure to ultrafine particles (UFP) due to the lack of personal sampling equipment available for this particle fraction. The logbook method has been proposed as a general method for exposure assessment. This method measures the time and concentration components of the time-weighted average concentration separately and could be suitable for investigation of UFP exposure. Objectives: In this study, we have assessed workers’ exposure to UFP in a ferrosilicon plant. The main tasks of the furnace workers were identified, and the logbook method was used in combination with stationary measurements of UFP taken as close to the identified task areas as possible. In order to verify the results, respirable particles were collected using stationary sampling in close proximity to the UFP measuring instrument, and personal full-shift sampling of respirable particles was performed simultaneously. Thus, exposure to respirable particles determined using the logbook method could be compared to the results of standard measurement. Methods: The particle number concentration of ultrafine particles was determined using a NanoScan SMPS. Respirable particle concentration and exposure were determined using a sampling train consisting of a pump, filter, filter cassettes, and SKC Cyclone for the respirable fraction. Attendance times for workers at each work location were registered via thorough observations made by the research team. Results: The logbook method for exposure estimation based on stationary sampling equipment made it possible to calculate UFP exposure for workers operating the furnaces at a ferrosilicon plant. The mid-size furnace and the large furnace were evaluated separately. The workers operating the largest furnace were exposed to 1.47 × 104 particles/cm3, while workers operating the mid-size furnace were exposed to 2.06 × 104 particles/cm3, with a mean of 1.74 × 104 particles/cm3. Substantial contributions from the casting area, ladle transport corridor, and both tapping areas were made. Exposure to respirable particles was 2.04 mg/m3 (logbook); 2.26 mg/m3 (personal sampling) for workers operating the large-sized furnace, 3.24 mg/m3 (logbook); 2.44 mg/m3 (personal sampling) for workers operating the medium-sized furnace, and 2.57 mg/m3 (logbook); 2.53 mg/m3(personal sampling) on average of all tappers. The average ratio of these two methods’ results was 1.02, which indicates that the logbook method could be used as a substitute for personal sampling when it is not possible to perform personal sampling, at least within this industry. Conclusions: The logbook method is a useful supplement for exposure assessment of UFP, able to identify the most polluted areas of the workplace and the contribution of different work tasks to the total exposure of workers, enabling companies to take action to reduce exposure.


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