 New research looking at what appears to be a major contributor to male infertility, aluminum, has powerful implications for the safety of childhood vaccinations and flu shots, which are loaded with the toxic metal. Researchers from both the UK and France found that the higher the level of aluminum inside a male's body, the lower his overall sperm count and quality of semen. Published in the Elsevier journal Reproductive Toxicology , the groundbreaking study looked at semen samples collected from 62 male patients. In accordance with World Health Organization (WHO) guidelines, semen analyses were conducted using a graphite furnace atomic absorption spectrometry method designed to assess aluminum concentration, and this was followed up with a cytological analysis using an aluminum-specific fluor, lumogallion. Going into the study, the researchers involved hypothesized that environmental pollutants like aluminum may be responsible for the steady decline in male fertility that has occurred primarily throughout the last 60 years in many industrialized nations. Focusing specifically on aluminum as a primary culprit, the team aimed to either confirm or dismiss a possible link between this common metal and sperm quality. Sure enough, their suspicions were confirmed. Aluminum, which can actually accumulate inside individual sperm cells, was found to be directly associated with damaged male fertility. Participants with oligospermia, a condition categorized by low concentrations of sperm, were found to have higher levels of detectable aluminum in their bodies, while those with low aluminum content had higher concentrations of healthy sperm. Among all the 62 donors, mean aluminum content was found to be generally high, averaging 339 parts per billion (ppb). However, some of the donors had exceptionally high aluminum levels in excess of 500 ppb, and these donors also had the worst quality and quantity of sperm overall, illustrating an exceptional inverse relationship between the two. 'There has been a significant decline in male fertility, including sperm count, throughout the developed world over the past several decades and previous research has linked this to environmental factors such as endocrine disruptors,' said Professor Christopher Exley, a leading authority on human exposure to aluminum at Keele University in the UK and leader of the study. 'Human exposure to [aluminum] has increased significantly over the same time period and our observation of significant contamination of male semen by [aluminum] must implicate [aluminum] as a potential contributor to these changes in reproductive fertility.' Watch out, parents: Childhood vaccines, flu shots all contain aluminum adjuvants These findings are an obvious cause for concern among parents, as many childhood vaccines are loaded with aluminum . According to the National Network for Immunization Information, the following vaccines are currently licensed to contain aluminum adjuvants, which include aluminum hydroxide, aluminum phosphate and potassium aluminum sulfate, also called 'alum': 