The agricultural destination of sewage sludge promotes the return of organic matter and nutrients to the soil, prevents contamination and degradation of hydric resources, and contributes to food and fiber production. In Brazil, the Resolution of the National Environment Council (Conama 375/06) and in the State of Paraná the Resolution of the State Environment Cabinet (Sema 021/09) established criteria and procedures for agricultural use of sewage sludge seeking to avoid risk to public health and the environment. This case study attempts to present the results of the destination of the sludge generated in the Sludge Management Units (SMU) in Curitiba Metropolitan Region (CMR), State of Paraná, Brazil from 2007 to 2010. Data analysis of agronomic parameters and inorganic substances (metals) of 99 batches of sewage sludge destined for agricultural use, based on 239 agronomic projects, was performed. The comparison of the characteristics of the batches generated in anaerobic and aerobic SMUs of CMR was also conducted. During the study, 88,166 t of sludge (33,404 dry tons) were destined for 2,288 ha of agricultural areas. The sludge provided 88 % of the lime, 74 % of N, 73 % of P₂O₅, and 35 % of K₂O for fertilizing the corn, soybean, bean, oat, wheat, green manure, and in the implementation and postharvest of stone fruit trees. The 80 benefited farmers reduced expenses with fertilizers and limestone, saving an average of US$813.45 per ha.

Sublethal exposure to pesticides can alter the survival and reproduction of a wide range of non-target organisms. However, it remains unclear whether this exposure can alter behaviours that are often essential for long-term population dynamics and maintenance, such as parental care. In this study, we tested the effect of pyriproxyfen exposure (an insect growth regulator) on maternal care in the European earwig, an insect that is both used in pest control in pip-fruit orchards and considered a pest in stone fruit orchards. We exposed 424 females at doses either 10 times lower, equivalent or 10 times higher than normal application rates in French orchards. As maternal care can change over the weeks of family life, we exposed the earwig mothers at five different days before and after egg hatching. We then measured the expression of ten forms of maternal care towards eggs and juveniles, six non-caring behaviours, eggs and juvenile development, metabolic reserves in mothers at egg hatching and females’ production of a terminal clutch. First, our results revealed that the three tested doses of pyriproxyfen were non-lethal and confirmed that maternal care decreased throughout both pre- and post-hatching family life. However, we did not detect any effect of pyriproxyfen on maternal care and non-care behaviours, eggs and juvenile development, quantities of lipids, proteins and glycogen in mothers at egg hatching, and on the production of a future clutch. Overall, these findings suggest that the maximal doses of pyriproxyfen authorized in French orchards is likely to have limited effects on the short- and long-term maintenance of populations of the European earwig and raises fundamental questions about the nature of the link between juvenile hormone and parental care in insects.

Assessment of contaminated food through the dietary intake is essential for human health. To investigate the health risk of rare earth element (REE) exposure to fruits and vegetables in mining areas in China, we collected 288 fruit samples and 942 vegetable samples from four representative mining points (Bayan Obo in Inner Mongolia, Weishan in Shandong, Maoming in Guangdong, Longnan in Jiangxi) and their control areas. The content of REEs was determined by inductively coupled plasma-mass spectrometry (ICP-MS). The total REEs in fruits from mining and control areas were 12.90 μg kg⁻¹ and 11.89 μg kg⁻¹, and in vegetables were 92.90 μg kg⁻¹ and 62.38 μg kg⁻¹, and the difference was statistically significant in vegetables (P = 0.048). The drupes had more REE concentration in fruits (68.41 μg kg⁻¹, 16.90 μg kg⁻¹ in mining and control areas, respectively) (P < 0.01), and the leafy vegetables had more REE concentration in vegetables (245.81 μg kg⁻¹, 123.51 μg kg⁻¹ in mining and control areas, respectively) (P < 0.01). With the enrichment of light rare earth elements (LREE), the REE distribution patterns coincided in mining and control areas and different types of fruits and vegetables. The health risk assessment indicated that the estimated daily intakes (0.02–0.06 μg kg⁻¹ day⁻¹, 0.53–1.22 μg kg⁻¹ day⁻¹ for fruits and vegetables, respectively) were lower than the allowable daily intake value (60.4 μg kg⁻¹ day⁻¹). In mining areas, REEs obtained from fruits and vegetables were insufficient to cause health damage to human beings. However, sustained exposure to low REEs, especially for children, still needs attention.