Commissioned and de-commissioned shooting ranges continue to pose an environmental and human health risk due to the accumulation of toxic Pb emanating from spent munitions. The phytotoxic effects of Pb accumulation in plants include inhibition of root growth and lowering of plant metabolism. The uptake of Pb by plants is directly affected by factors such as plant species and physicochemical properties of the soil. However, scientists and researchers have leveraged on the ability of some plant species to accumulate and tolerate Pb toxicity and applied them in the control and management of Pb pollution of shooting range soils. This technique is called phytoremediation. The objectives of this review are: (i) to assess the prevalence of toxic Pb metal in plant species growing in and nearby shooting ranges, (ii) to establish the soil-plant mechanistic pathway for Pb (iii) discuss the effectiveness of phytoremediation technology towards shooting range soil amendment.

Background: Toxic metals in cosmetic products can lead to serious health problems among consumers. Skin lightening cosmetics are popular among women who may be unaware of prevalence of toxic metals in such products. Purpose: This study assessed the content of toxic metals in cosmetic products imported into Botswana. There are currently no regulations in Botswana governing maximum contaminants limits for contaminants such as metal ions in cosmetic products. Research Design: Sample analysis was carried out using inductively coupled plasma optical emission spectrometry after microwave-assisted acid sample digestion. Results: Total concentrations of metals were in the order Pb > Ni > Cr > As. The concentrations of metals analysed were in the range of 45.75–193.60; 2.99–9.50; 3.32–7.41 and 1.95–4.52 mg/kg for Pb, Ni, Cr and As respectively. The concentrations of Pb in all 14 samples exceeded the maximum impurity level of 10 mg/kg in cosmetics as per the United States Food and Drug Administration (US FDA). Concentrations of Ni, As and Cr were also higher than the set US FDA limits in some cosmetic samples under study. A human health risk assessment was conducted using hazard quotient, average daily intake and health risk index. A hazard quotient of greater than one was determined for Pb (HQ ∼ 177.0–749.2) in all 14 cosmetic samples investigated indicating potential adverse effects to human health. Conclusion: Overall results of total concentration and health risk assessment indicate that cosmetic products imported into Botswana are harmful to consumers. Therefore, quality control measures should be enforced to ensure metal concentrations in facial cosmetic products do not exceed regulatory limits.

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Latent fingerprint detection and visualization remains a challenge especially where problems of poor contrast, auto-fluorescent surfaces and patterned backgrounds are encountered. As a result there is an increasing interest in the development of simple, cost effective, rapid and yet accurate methods for latent fingerprint detection and recovery. Herein, this paper reports the synthesis of bright blue photoluminescent carbon dots (C-dots) via an eco-friendly and simple one-step microwave-assisted carbonization of potato peels’ biomass. The C-dots were prepared in only 3 min and ground into powder and used without any further treatment. The as-prepared C-dots were characterized using atomic force microscope, Fourier transform infra-red spectroscopy and X-ray diffraction with an average size of 1.0[Formula: see text]nm. The optical properties of the as-prepared C-dots were studied by UV-Vis spectroscopy and spectrofluorometer which established an excitation and emission wavelengths of 390[Formula: see text]nm and 480[Formula: see text]nm, respectively. Owing to their strong solid state fluorescence, the as-prepared C-dots’ powder was successfully used in latent fingerprint detection and imaging on porous and nonporous surfaces. Latent fingerprints were recovered with high resolution and excellent quality providing sufficient details for individual identification. These findings demonstrate that C-dots derived from biomass have a great potential in latent fingerprint analysis for forensic applications.

The quest for the design and synthesis of carbon dots with anti-counterfeit properties that are derived via green, environmentally friendly and economical procedures is a continuous process. Carbon dots (C-dots) derived from biowaste are cheap to synthesize, possess good photo-stability and high synthetic yield, making them applicable in the anti-counterfeiting of currency. Herein, we report a novel eco-friendly, cheaper, and faster method for the synthesis of carbon dots with strong photoluminescence properties from monkey orange fruit (Strychnos spinosa) biowaste. The presence of the hydroxyl and carbonyl functional groups of the carbon dots were determined by the Fourier transform infrared spectroscopy (FTIR). The carbon dots showed strong blue emission fluorescence (emission wavelength of 452[Formula: see text]nm) when excited at 330[Formula: see text]nm. The morphology and size were determined by the atomic force microscopy (AFM) which indicated amorphous and spherical nanoparticles with an average size of less than 2[Formula: see text]nm. The no-crystallinity of the as-prepared carbon dots was confirmed using X-ray diffraction which showed the graphite-like structure. The carbon dots were produced and demonstrated good photo and chemical stability as well as high covert properties. The anti-counterfeiting of currency application by the synthesized carbon dots was demonstrated when the subsequent gel ink printed on the currency showed excellent chemical stability when exposed to washing with water, ethanol, and acetone. It also showed superior photostability when exposed to UV light at 365[Formula: see text]nm and daylight for an extended period of up to 6[Formula: see text]h. This work provides a facile, economical, and green approach for large scale production of carbon dots from the abundant biowaste.