Hygiene and environmental health advances最新文献

Increasing evidences have revealed a close relationship between various environmental exposures and reproductive health. The real-world complex exposure scenario along with intricate interactions effects of these exposures has high demands of exposome-wide association studies for human risk assessment. With the development of exposomic studies, applying hair exposome to link environmental factors and reproductive health outcomes has obvious potential advantages. However, the reliability of utilizing hair to characterize exposome is always of high concern for researchers. In this review, we briefly summarized studies about the effects of environmental exposures on several typical reproductive health outcomes, described state-of-the-art situation of applying hair exposome for reproductive health risk assessment, elucidated the advantages (e.g., containing abundant exposure factors, low expenses for sampling, and tracing exposure history), and proposed the unsolved issues in this area. We also conducted a comprehensive discussion about the reliability of various hair biomarkers and primarily established the biomarker databases. Finally, a standardized framework on using hair exposome for reproductive health study was proposed to provide fundamental approach for future studies. We concluded that it is promising to apply hair exposome to evaluate the effects of the environmental factors on human reproductive health.

The CHemical Exposure and Children's Health (CHECH) study is an ongoing pregnancy cohort study in Tianjin, China. This paper describes the background, aim and the study design, which can be followed by future researchers to design and conduct similar studies. The abundance and the potential adverse health outcomes of endocrine disrupting chemicals (EDCs) is concerning. More notably, developing fetuses and infants are more vulnerable to EDCs exposure. The CHECH study aims to investigate the importance of early life exposure to multiple EDCs (phthalates and their metabolites, bisphenol A and their substitutes, perfluorinated compounds and poly brominated diphenyl ethers) for multiple health outcomes in Chinese children, namely sexual development, neurodevelopment, metabolism and growth, as well as asthma and allergy. A total of 2238 pregnant women were recruited in Tianjin from May 2017 to April 2021 with a response rate of 90 %. Among these women, 2255 children were born with available information, including 47 pairs of twins. Urine samples were collected from pregnant women and children, while air and dust samples were obtained from the home environment during pregnancy and infancy periods. Information on children's health was gathered through physical examinations and questionnaires. The CHECH study, which collected exposure information and health outcomes at multiple time points, will contribute to the understanding of prenatal exposure to EDCs and their impact on children's health, thereby facilitating the development of risk assessments aimed at reducing exposure and associated health risks.

Objective

Little is known about school environmental health (EH) problems in private schools. This study identified and compared the school EH related issues and policies between private and public schools in the U.S.

Methods

School EH information was collected from school administrators on two levels – in New York State (NYS) and nationwide. In NYS, questionnaires were developed and distributed to administrators from both public and private schools via conferences (2015–2016). Nationwide survey data were obtained from the 2014 School Health Policies and Practices Study. We compared the perceived school environment as well as policies related to identification and training on EH issues between private and public schools both in NYS and nationwide.

Results

In NYS, both private and public schools reported limited use of proactive approaches in identifying EH issues. Compared to public schools, more private school respondents reported poorer perceived indoor air quality (IAQ) (30% vs. 0%), along with less routine training and lower use of policies that help improve air quality in school. Nationwide, fewer private schools implemented indoor air quality management programs (18% vs. 58%) and were able to always meet ventilation standards (44% vs. 64%) than public schools. Staff members in private schools received less required training on a wide range of EH issues than staff members in public schools.

Conclusion

U.S. private schools reported worse perceived indoor air quality than public schools and a lack of awareness and protective policies. Future environmental research and implementation of policies are needed in private schools.

Alginates are products used as impression materials in dentistry and prosthetics. They consist of polymers, calcium alginates mixed with diatomite and additives. Recently, the occurrence of severe silicosis associated with exposure to respirable dust of such materials has increased the scientific interest in understanding how these materials may pose a toxicological problem to workers. The primary objective of this study is to improve the understanding of both the existence and the characteristics of the toxicant(s) contained in these materials, with the goal of better defining the risk assessment for this occupational setting.

Two commercial dental alginates were subjected to a mineralogical, microchemical and spectroscopic investigation. The results indicate the presence of a significant amount of diatomite, clearly identified by micromorphology and formed mainly by cristobalite. The respirable fraction of the dust represents at least 30  % of the total number of particles, and this fraction contains a relevant amount of crystalline silica particles. Conversely, the investigated alginate materials do not exhibit the presence of radical species.

The results obtained confirm that the cristobalite detected originates from the high-temperature transformation of amorphous silica during the calcination process of diatomite, prior to mixing with the other components. The same process also produces wollastonite (CaSiO₃), which, like cristobalite, is a crystalline phase known for its toxicological effects. The present findings call for a rethinking of dental alginates with regard to the definition of their health risks for technical operators.

Hair has long been explored as a potential biomarker of lead exposure since lead is readily adsorbed into hair's keratinous matrix; however, the utility of hair as a biomarker for lead exposure is hampered by its susceptibility to external contamination: lead particles attach to the exposed hair surface, confounding estimates of endogenous concentrations. This study describes the development of a hair screening tool, in which the confounding influence of external contamination are mitigated by focusing on the unexposed hair root, to predict elevated blood lead levels (BLLs). This tool requires a single strand of scalp hair, which is analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Forty-four (44) workers with high potential for lead exposure, and 63 reference individuals (with no known lead exposure) volunteered for the study. Hair lead level (HLL) thresholds were developed using methods from clinical assessment to screen exceedances of BLL thresholds at 10 and 15 µg/dL. Hair from both groups showed significantly lower lead concentrations in below-scalp portions compared to above the scalp (above-scalp was 11.2 times higher in workers, and 3.7 times higher in reference group). Hair lead concentrations below the scalp in workers significantly predicted BLLs. HLL thresholds for screening BLLs were 0.60 mg/kg and 0.75 mg/kg for BLLs of 10 µg/dL and 15 µg/dL, respectively. These HLL thresholds yielded high sensitivity (>85%), and slightly lower specificity (67% and 33%, for BLL thresholds of 10 µg/dL and 15 µg/dL, respectively). This study provides reference HLLs in non-contaminated portions of hair (<0.097 mg/kg), shows the significance of external contamination on exposed portions of hair even in a reference population, and assesses the effectiveness of below-scalp hair as a biomarker of elevated lead exposure. This hair screening tool effectively predicted BLL exceedances and could be considered as a non-invasive alternative to blood sampling.

By virtue of its availability of arable land, tropical climate, and abundance of water resources, Brazil is one of the largest agricultural and livestock producers in the world, with agribusiness geared towards global trade. Consequently, the country appears on the international scene as one of the main consumers of pesticides. This article presents the current panorama of pesticide use in Brazil and highlights the tendency of government permissiveness and support in this sector, through the increase in the number of registrations granted annually and strategies to modify the current legislation. The methodological procedures were: discussion about causes and consequences of pesticide use, considering economic interests, social and environmental impacts; collection and analysis of data made available by official Brazilian agencies on the pesticides marketing and main cultivated products; study of Bill 6,299/2002; and positioning of public institutions linked to work, health and the environment, through the technical notes issued by them. Conceptually, we found our arguments on Political Ecology and Geography ideas to demonstrate that the exacerbated use of pesticides in Brazil is a great environmental and social injustice, contaminating natural resources and the Brazilian population that handles or consumes food and water with high levels of residues. The data reveal that the productive specialization has led to a progressive increase in the use of pesticides in Brazil, and the government has been extremely permissive of, and even conniving with, the interests of companies linked to agribusiness, making the process of evaluating and releasing pesticide products even less rigid.

CeO₂ and CuO nanoparticles (NPs) are used as additives in petrodiesel to enhance engine performance leading to reduced diesel combustion emissions.   Despite their benefits, the additive application poses human health concerns by releasing inhalable NPs into the ambient air.  In this study, a bioinspired lung cell exposure system, Dosimetric Aerosol in Vitro Inhalation Device (DAVID), was employed for evaluating the toxicity of aerosolized CeO₂ and CuO NPs with a short duration of exposure (≤10 min vs. hours in other systems) and without exerting toxicity from non-NP factors.  Human epithelial A549 lung cells were cultured and maintained within DAVID at the air-liquid interface (ALI), onto which aerosolized NPs were deposited, and experiments in submerged cells were used for comparison.  Exposure of the cells to the CeO₂ NPs did not result in detectable IL-8 release, nor did it produce a significant reduction in cell viability based on lactate dehydrogenase (LDH) assay, with a marginal decrease (10%) at the dose of 388 μg/cm² (273 cm²/cm²).  In contrast, exposure to CuO NPs resulted in a concentration dependent reduction in LDH release based on LDH leakage, with 38% reduction in viability at the highest dose of 52 μg/cm² (28.3 cm²/cm²).  Cells exposed to CuO NPs resulted in a dose dependent cellular membrane toxicity and expressed IL-8 secretion at a global dose five times lower than cells exposed under submerged conditions.  However, when comparing the ALI results at the local cellular dose of CuO NPs to the submerged results, the IL-8 secretion was similar.  In this study, we demonstrated DAVID as a new exposure tool that helps evaluate aerosol toxicity in simulated lung environment. Our results also highlight the necessity in choosing the right assay endpoints for the given exposure scenario, e.g., LDH for ALI and Deep Blue for submerged conditions for cell viability.

Human excreta can be used as biofertilizers due to their nutrient and organic matter content. Nevertheless, the behavior of microorganisms should be investigated, as enteric pathogens can accumulate in the soil. Therefore, we evaluated the survival and transport of two enteric bacteria (E. coli and Salmonella enterica) and two enteric virus surrogates (MS2 and ΦX-174 bacteriophages) when applied as contaminants of four biofertilizers on Lactuca sativa production. The study was carried out in lysimeters outdoors with repacked silt loam soil, using a randomized block design (RBD) with six treatments and three replicates. Biofertilizers were urea-treated feces, feces composted with organic waste, stored liquid urine, and struvite and were inoculated at 10⁶–10⁷ cfu/pfu g⁻¹ of E. coli and bacteriophages strains and 10⁷–10⁹ of S. enterica. Soil amended with composted feces exhibited the lowest decimal reductions (T₉₀) for the microorganisms evaluated, with 10.2 days for E. coli, 11.9 days for S. enterica, 22.2 days for MS2, and 3.7 days for ΦX-174. Urea-treated feces temporarily hindered the growth and survival of E. coli and S. enterica in the soil. However, both bacteria were present after one month, while MS2 showed a stable concentration with this biofertilizer. E. coli presented a stable behavior when applied with urine, whereas MS2 was stable with urea-treated feces, urine, and struvite. ΦX-174 and S. enterica were not considered good representatives of most resistant enteric pathogens’ behavior in the soil during food production since they were not detected in leachate and showed a rapid die-off in soil. E. coli leached faster and in higher concentrations than MS2, which presented higher concentrations in deeper soil layers, from 10 to 20 cm. Therefore, using urine, struvite, and urea-treated faces implied a higher chance of infection, as a decimal reduction time was not observed during the 36 days of the experiment. As a result, in short-term cultures, it is recommended that additional hygiene barriers are taken to avoid infection since E. coli and MS2 were still detected at the end of the experiment. An interval of 90 days between fertilizing and harvesting is recommended to prevent pathogen infection. These results are the basis for a quantitative risk assessment of human excreta-based biofertilizers for food production.