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Toxicity of organic chemical compounds, including benzene, toluene, ethyl benzene and xylene (BTEX), is a major concern because of their induction of adverse effects in organisms, including reproductive abnormalities. In the present study, we investigated impacts of chronic exposure to BTEX at 25 µg L −1 on the ovaries of the freshwater leech Erpobdella johanssoni at the cytological and molecular level. Based on light and transmission electron microscopy, we found that somatic cells and vitellogenic oocytes of the treated animals underwent degenerative changes, such as cytoplasmic vacuolization, mitochondrial alterations, and nuclear DNA condensation, as compared with normal. The comet test supported histological and ultrastructural results and showed that BTEX exposure induced significantly more DNA fragmentation in the ovary cells of treated leeches than in controls (p < 0.0001). Overall, we concluded that BTEX-induced deterioration in ovarian cells suggests the genotoxicity of BTEX on oogenesis in leech, which could impair their reproduction.

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Modern agriculture's biggest challenge is finding sustainable and environmentally peaceful fertilizers. This study aimed to compare the physicochemical properties of some non-traditional P-Sources such as bovine bone-ash (BA-600 and BA-700) and bone-char (BC-600 and BC-700), and commercial phosphate rock (PR). Various extraction techniques were applied to assess phosphorus solubility and availability of the P-Sources mentioned above compared to single-superphosphate (SSP). Additionally, an incubation experiment was carried out to investigate the phosphorus availability and organic carbon in calcareous soil, which received different P-Sources and N-K fertilizers and incubated for up to 120 days (≃29 °C) arranged in a three-factor completely randomized design. The physicochemical properties of bone-char (BA-600 and BA-700) and bone-ash (BC-600 and BC-700) revealed that hydroxyapatite is present in both P-resources. Soluble and available phosphorus followed the order: BA-600>BC-600>PR for all extraction techniques. Relative to SSP fertilizer (100%), Soluble-P of water and diluted-H2SO4 (0.005 M) were nearly closed. In the incubation experiment, significant differences (P<0.05) were observed between the levels of N-K treatment, incubation time, and P-sources on soil pH, soluble calcium, and Olsen-P. Statistically, N-K fertilizers addition to P-sources-amended soil significantly (P<0.05) increased the calcium concentration in all treatments. Olsen-P was in order: SSP > BC-600 > BA-600 > PR > control; the highest significant incubation time was 80 days. The highest percent organic carbon was recorded in the BC-600 amendment after 100 days of incubation, with no clear effect for N-K fertilizers addition. Both BA and BC are potential phosphorous resources of a sustainable nature, with a preference for bone char as a source of non-microbially degradable organic carbon.

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