Plastic pollution is a pervasive and growing global problem1-4. Chemicals in plastics are often not sufficiently considered in the overall strategy to prevent and mitigate the impacts of plastics on human health, the environment and circular economy5-7. Here we present an inventory of 16,325 known plastic chemicals with a focus on their properties, presence in plastic and hazards. We find that diverse chemical structures serve a small set of functions, including 5,776 additives, 3,498 processing aids, 1,975 starting substances and 1,788 non-intentionally added substances. Using a hazard-based approach, we identify more than 4,200 chemicals of concern, which are persistent, bioaccumulative, mobile or toxic. We also determine 15 priority groups of chemicals, for which more than 40% of their members are of concern. Finally, we examine data gaps regarding the basic properties, hazards, uses and exposure potential of plastic chemicals. Our work maps the chemical landscape of plastics and contributes to setting the baseline for a transition towards safer and more sustainable materials and products. We propose that removing known chemicals of concern, disclosing the chemical composition and simplifying the formulation of plastics can provide pathways towards this goal.
Of the 237 women, 92 (38.8%) had experienced both a normal and a toxaemic pregnancy, and 72 (78%) contrasted the sense of well-being associated with a normal pregnancy with the malaise and minor symptoms characteristic of the toxaemic condition. The striking feature of these early minor symptoms of toxaemia was their close resemblance to those of premenstrual syndrome noted in an earlier investigation (Greene and Dalton, 1953), most patients confirming that the minor symptoms during their toxaemic pregnancy were similar, though of increased severity, to those experienced in the premenstruum, irrespective of whether the onset of premenstrual syndrome had preceded or followed the toxaemic pregnancy.
Reproductive EndocrinologyNeuron Development and MigrationEmbryologyKallmann Syndrome
Neurons expressing luteinizing hormone-releasing hormone (LHRH), found in the septal-preoptic nuclei and hypothalamus, control the release of gonadotropic hormones from the anterior pituitary gland and facilitate reproductive behaviour. LHRH-expressing neurons are also found in the nervus terminalis, a cranial nerve that is a part of the accessory olfactory system and which projects directly from the nose to the septal-preoptic nuclei in the brain. During development, LHRH-immunoreactivity is detected in the peripheral parts of the nervus terminalis before it is found in the brain. Using a combination of LHRH immunocytochemistry and tritiated thymidine autoradiography in fetal mice, we show that LHRH neurons originate in the medial olfactory placode of the developing nose, migrate across the nasal septum and enter the forebrain with the nervus terminalis, arching into the septal-preoptic area and hypothalamus. Clinically, this migratory route for LHRH-expressing neurons could explain the deficiency of gonadotropins seen in 'Kallmann's syndrome' (hypogonadotropic hypogonadism with anosmia).