Most studies focus on the US so this offers a different perspective. Additionally, Australia is the largest producer of Lead, and has issues with Lead paint, Leaded petrol and mining/smelting emissions, contributing to extremely high levels of Lead within the country itself. After a 21 year lagg Lead accounted for 29.8% of the variance for assaults, and additionally found weak correlations between Lead and people committing fraud, adding to the growing research which hypothesizes that Lead causes aggression.

Ohio State University, Columbus

Stretesky and Lynch establish a background about the effects Lead has on the biology
and psychology of a person, stating how the ‘“neurotoxicity hypothesis”’ describes how Lead
affects “neurotransmitter[s] and hormonal systems in a way that may induce aggressive and
violent behavior” 

Leads effect on the body

Taylor, Mark Patrick, et al. “Erratum to: The Relationship between Atmospheric Lead Emissions
and Aggressive Crime: an Ecological Study.” Environmental Health, vol. 15, no. 1, 2016,
doi:10.1186/s12940-016-0204-2.


Erratum to: The Relationship between Atmospheric Lead Emissions and Aggressive Crime: an Ecological Study

Boutwell pursued this extension since his previous study drew upon the total violent crime, and this metric can bias results because of “spatial autocorrelation”, or “the tendency for certain outcomes to cluster together geographically for reasons other than a causal association between those two variables”, in turn by deconstructing violent crime, the correlation between crime and BLL would further be supported since confounding variables would be minimized (3). In turn, Boutwell refined his crimes beyond traditional categories into, “...crimes involving a firearm, assault (with or without a firearm), 3) robbery (with or without a firearm), homicides and rape” (4). Several important findings were discovered with these refined groups, firstly “...increasing the percentage of elevated BLL [blood lead level] by just 1 percentage point was associated with 1.03 times greater risk for firearm crime...assault crime...a greater risk for robbery… and homicide” , additionally with a p-value = .05 these results mean Leads effect on these specific crimes is highly unlikely due to chance and therefore this relationship is less likely to be due to other factors like “spatial autocorrelation” and Leads affect is therefore significant in correlating with crime (7). Laslty, the other major finding from Boutwells second paper is that although the Lead and crime link is positive in regard to rape, it “wasn’t statistically signinficant”at a confidence level of p = .05, in which the results are not most likely due to chance. 

Lead and Crimes effect on St. Louis Violent Crime

Lead and Crime in Australia

Unlike other studies, Nkomo’s focuses on a 3rd world country, while previous research has focused on “developed countries” which supports this phenomenon
by highlighting its not a developed country problem or an interaction between Lead and a confounding variable localized to 1st world countries, additionally South Africa also suffers from continual lead use in “medicine” and “traditional ammunition” in turn its hasn’t been fazed out and it’s affecting people continuously with the median blood level for the sample at 5.6 ug/dL (p<.001) (136-137). Most importantly, however, blood lead levels were significantly related to physical violence (p < .0001) and for those with “BLLs ranging from 5 to 9.99μg/dL were associated with physical violence (p= 0.03) and BLLs ≥ 10μg/dL were associated physical violence and ghting (p = 0.02 and p = 0.01, respectively)” 

Learn Before

Related